In an effort to make laptop computing as painless as possible, many companies have designed trays and pads on which you can easily rest your laptop while you work. This week, I’ve been testing a few laptop trays that are designed specifically to cool hot laptops and, in turn, cool laps.

I tried out trays from Logitech (LOGI), Microsoft (MSFT) and Belkin that cost $30 each and use fans to cool the underside of the laptop, as well as a larger $50 Belkin tray that has a fan and some extra features. I tried a $20 tray from Kensington that doesn’t include a fan, but elevates the laptop to allow air to circulate under it and keep the hot computer off your lap. None of the trays had cushions for comfort.

Logitech Cooling Pad N100

Of the trays with fans, Logitech’s Cooling Pad N100 ran the quietest — so quiet that it was hard to tell if it was on, aside from the fact that my lap was cooler. The trays with fans kept my lap cool, but the Kensington tray didn’t work quite as well and left my lap feeling a bit warmer than the others. All the trays raise the laptop higher and closer to eye level, a feature that keeps you from hunching over while reading the screen. I liked the $50 Belkin Laptop Cooling Lounge for its generous size, sturdy feel and three adjustable heights.

Even though these trays help to keep your laptop cooler, they don’t do anything about your keyboard, which, on some laptops, also can get hot — especially where your wrists rest. I noticed that my Lenovo ThinkPad X60’s wrist rest area was still warm when I used this laptop with each tray.

Of the $30 trays, the Logitech Cooling Pad N100 (Logitech.com) was the widest, measuring 14.4 inches across. Its gray and green colors are a welcome switch from the bland white used on most trays. The fan on this and the other trays is powered by a short USB cable that plugs into a USB port on your laptop. An indent in the Logitech tray holds the cable flush against the bottom of the tray when not in use.

Logitech says its tray’s single fan has a minimal drain on your laptop’s battery — draining five minutes of total battery time while using a Hewlett-Packard (HPQ) laptop playing a DVD in one company test. I don’t think many people will use these cooling trays on-the-go and will, instead, use them at home where their laptop can easily plug into a wall socket and power isn’t a problem.

Microsoft’s $30 Notebook Cooling Base (Microsoft.com/hardware) will come in white and black when it’s available early this summer (Amazon is accepting orders now). Compared with the Logitech, its fan was a little noisy. But the Microsoft tray was considerably smaller and thinner, making it more portable.

The tray has a fold-away stand that raises it up about two inches on one end. Its USB cable has a clip on its end so that it can loop around and attach to itself, rather than tuck neatly into the tray. Microsoft says that based on an 18 Ampere per hour battery, the Notebook Cooling Base will lessen battery life by only about 4%.

Belkin’s $30 Laptop Cooling Pad (Belkin.com) reminded me of Microsoft’s offering in shape and size. Both are square, unlike the rectangular Logitech tray, and both have flip-out stands and a wave-like shape that leaves open space under the laptop. Belkin says that its Laptop Cooling Pad uses no more than 5% of a laptop’s battery. But the Belkin fan was slightly louder than Microsoft’s and considerably louder than Logitech’s. It also seemed to be a bit stronger, blowing more air than the others.

Belkin’s Laptop Cooling Lounge (available at OfficeMax.com) was the largest tray I tested, wider and deeper than the Logitech tray by a few inches in width and depth. A piece under the tray can be adjusted to raise it to one of three heights, allowing it to rest comfortably on a lap because it raises up or down using a roll of plastic rather than a stand that might dig into your thighs. This tray’s fan was louder than the Microsoft and Logitech fans, but I ignored the noise because it was so comfortable.

When closed, the $20 Kensington LiftOff Portable Notebook Cooling Stand (Kensington.com) resembles a one-inch thick plastic briefcase with handles. Once the stand is opened, one piece lies flat while the other piece is raised to one of two heights, elevating the laptop. The top raised piece supports the laptop and has a hole in the center, designed to allow air to pass under the laptop, thus cooling it off without a fan. However, this no-fan method left my lap feeling a bit warm. When you’re done with the Kensington LiftOff, you can close it shut and carry it using its built-in handles. But its plastic parts felt flimsy and unstable, especially compared with the Belkin Laptop Cooling Lounge.

Of course, you could always just use a regular laptop tray without a built-in fan. It won’t cool your laptop, but if it’s thick enough, it at least could prevent your lap from feeling the computer’s direct heat. Just be aware that hot wrist rests won’t be cooled by these trays.

Edited By Walter S. Mossberg

• Email us at mossbergsolution@wsj.com. Find this and other columns and videos online free at the All Things Digital Web site: http://solution.allthingsd.com

But several companies now sell wireless mice designed especially for laptop users for whom the laptop touch pad just won’t do. These mice are small, sleek, colorful gadgets that more fashion-conscious computer users can happily show off in an airport, in a coffee shop or on campus.

See a chart comparing the three mice

This week I tested three entry-level mobile mice designed for laptops, from Logitech (LOGI), Microsoft (MSFT) and Kensington Computer Products Group. These $30 mice include a USB receiver that plugs into a laptop, allowing the mouse to work wirelessly. When not in use, this receiver fits snugly beneath the mouse, turning its power off to save battery as it snaps into place. These mice are also somewhat smaller than regular mice so they can easily slip into a laptop bag.

Mobile mice are now more stylish than the traditional desktop mice, and like laptops and digital cameras, come in various shapes and colors. The mice I tested are available in pink, white, red, blue, orange and gray. Next week, the Microsoft mouse I used will be available in shades of pomegranate, aloe, dragon fruit (dark pink) and milk chocolate; a khaki-colored shade called crème brûlée will follow in June.

I tried Logitech’s $30 V220 Cordless Optical Mouse in black, Microsoft’s $30 Wireless Notebook Optical Mouse 3000 in aloe, and Kensington’s $35 Ci75m Wireless Notebook Mouse in orange. To gain some perspective on high-end mobile mice, I also looked at two pricier options from Logitech: the $50 V470 Cordless Laser Mouse with Bluetooth (instead of a USB receiver) and the $70 VX Nano Cordless Laser Mouse.

My vote for a favorite low-end mobile mouse had me struggling between portability and comfort. But overall, I found that the Logitech V220 offered the best combination of small size and usability. The Microsoft mouse was also comfortable to use, but its slightly bulkier size made it less portable, and it didn’t feel as sturdy as the Logitech. While the Kensington was the flattest and most portable, it wasn’t as comfortable to use as the Logitech or Microsoft mice.

To conserve battery, all three of these mice go into low-power mode after 10 minutes of nonuse, but none of them turns off completely. Battery indicators light up when juice is running low. According to company estimates, the Microsoft mouse has a battery life of over six months and the Logitech mouse has a battery life of up to six months. The Kensington mouse’s battery life was estimated to be three months. I didn’t use any of them long enough to prove the company claims.

These mice are compatible with Macs and PCs, and are plug-and-play — meaning you don’t need to install any additional software to make them work. I used each on laptops running Mac OS X and Windows Vista without any problems. The Microsoft and Logitech mice also can work with their own special software programs, but the extra features, such as reassigning a mouse button to open an application, aren’t really necessary for the average user.

The $30 Logitech V220 fit comfortably in my hand, with rubber grips on its sides and a generously sized, smooth-gliding rubber scroll wheel that made it easy to use. This scroll wheel can be nudged to the left or right for horizontal scrolling, a feature found on most of Logitech’s mice.

Unlike the Microsoft and Kensington mice, which show flashing red sensor lights, the Logitech uses an invisible optic sensor. This sounds cool, but because the mouse doesn’t use any lights, it can be left on accidentally. I did this a few times before remembering to stow the USB receiver in the mouse to automatically turn off its power.

Of the three, the Logitech mouse was the only one with a manual on/off switch — so you can turn it off without snapping the USB receiver into place in the mouse. This could save frequent travelers from having to detach the USB receiver every time they want to turn off the mouse, and could let people keep the receiver plugged into the laptop.

Kensington’s $35 Ci75m was the flattest mouse by far, making it a cinch to slip it into the outside pocket of my already full laptop bag on a train trip to New York. And this mouse has a bonus feature: It can work wirelessly or with a USB wire, which wraps up inside the mouse and serves as a backup in case the mouse runs out of battery. I tested this by removing the batteries and using only the USB wire, and it worked like a charm.

I also liked the way the Kensington USB receiver disappeared into the body of the mouse, while the Microsoft and Logitech receivers protruded a bit when stowed, adding to the thickness of the mouse when tucked into a laptop pocket.

But though this bright orange mouse received approving feedback from passersby, it wasn’t all that comfortable to use after a while. Its flatness saved room in my bag, but didn’t give my hand much support. It also felt flimsier than the Logitech, and its small wheel wasn’t as satisfying to use.

I received early test units of Microsoft’s $30 Wireless Notebook Optical Mouse 3000 in aloe, pomegranate and milk chocolate.

This mouse has rubber sides for a better grip, like the Logitech, and an arched shape for comfort. Its wheel is slightly smaller than Logitech’s, though its overall size was bigger and more like that of a regular mouse — not one designed specifically for mobile use. But even though the Microsoft mouse was larger, it didn’t feel as solid as Logitech’s; rather, it felt more like the thin Kensington. Its right and left buttons felt less stable, and its wheel didn’t roll as smoothly.

I did like Microsoft’s nod to new colors, and the aloe — a cool hue of green — was my favorite.

For people who don’t mind spending a little extra money on a mouse, the $50 V470 Cordless Laser uses Bluetooth, eliminating the need for a USB receiver altogether. It took only a couple seconds to pair this mouse to a MacBook with built-in Bluetooth, and it worked smoothly. A manual on/off switch on this mouse’s underside can help to conserve battery.

The $70 Logitech VX Nano Cordless Laser is sleek with shiny black accents and a silver-edged wheel. The “Nano” in this mouse’s name refers to its ultra tiny USB receiver, which sticks out only about a quarter of an inch when plugged in, so it can be left in a laptop at all times for ease-of-use. If needed, this receiver can be hidden away in the cavity of the mouse, under a snap-on lid. I used the VX Nano to glide around Web pages and Word documents with buttery smoothness.

No matter what mouse you choose to use with your laptop, most will be considerably more comfortable than touch pads and trackpoints, especially while working on long, mouse-intensive projects. But of the three lower-end mobile mice, the Logitech V220 Cordless Optical Mouse delivers the best combination of comfort and transportability.

The chart below (click on it to make it larger) compares features of the three mice described in this column.

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This week, I tested three such replacement options: two keyboard sets that operate wirelessly using Bluetooth — the replacement for wires running short distances — and a stand-alone wired ergonomic keyboard made for touch typists who value comfort during long hours in front of a computer screen.

Top left: $150 Logitech Cordless Desktop MX 5000 Laser. Top right: $65 Microsoft Natural Ergonomic Keyboard 4000. $150 Microsoft Wireless Entertainment Desktop 7000.

The two wireless sets I used are Microsoft Corp.’s Wireless Entertainment Desktop 7000, which came out just a few months ago, and Logitech Inc.’s comparable but older Cordless Desktop MX 5000 Laser, which has been available for about a year and a half. Each costs $150. These keyboards have built-in shortcuts that make them handy to use on or off the desk when browsing through digital media like photos, videos and music.

I also tried Microsoft’s wired $65 Natural Ergonomic Keyboard 4000. It incorporates some shortcut buttons of its own, but stands out more because of its appearance: its keys are split into two groupings for right and left hands and each side slants upward in the center around an arch, forcing your hands to rest more naturally as if positioned to shake. The keyboard comes with a detachable wrist rest that raises your wrists a third of an inch above the rest of the keyboard.

Each product brought something slightly different to the table: The ergo offers comfort and functionality; the wireless Logitech has a multifunctional mouse and a keyboard with a built-in LCD; the wireless Microsoft shows off a sleek look and 17 touch-sensitive buttons. As a touch typist, I preferred Microsoft’s Natural Ergonomic Keyboard 4000 for its hand-relaxing setup and 13 shortcut buttons. I’m using it now to type this column, and my fingers have less distance to go before reaching a key than on a regular keyboard.

The basic functions of these keyboards/keyboard sets work out of the box on Mac and Windows operating systems, but their extra features work only after installing included or downloaded software, and neither the wireless Microsoft set nor the Logitech set will work on a Mac, period. Both companies claim that these products will work with Windows Vista, Microsoft’s newest operating system, but the ergonomic keyboard’s extra bells and whistles didn’t work properly on my Vista laptop.

I easily got the wireless Logitech and Microsoft keyboard sets communicating with their corresponding Bluetooth receivers on PCs and laptops. I pressed a Connect button on the base of each set’s mouse and keyboard before pressing the same button on the USB Bluetooth receiver and a few seconds later, I was in business.

The Microsoft and Logitech wireless desktops use USB plug-in Bluetooth receivers to connect the computer with the mouse and keyboard. Both mice operated on rechargeable batteries and must be docked occasionally for recharging, which is annoying — especially if you’re forgetful. But each will fully recharge in two hours, giving two and three weeks for the Logitech and Microsoft mice, respectively. Both mice get enough juice for a full day of usage after charging for 10 minutes.

Both keyboards use regular keys and a series of touch-sensitive buttons that work when you hover your finger over the intended button and touch it very slightly. Logitech’s touch-sensitive media buttons are relegated to the far left of its keyboard, including zoom and volume buttons that adjust with a finger flick up or down. Microsoft’s touch-sensitive keys line the entire top edge of its keypad.

Logitech’s wireless keyboard is about two inches wider than Microsoft’s, and for good reason: the Microsoft keyboard lacks a numeric keypad on its far right side, a feature that I missed. In place of the keypad are a set of directional buttons that mimic the basic functionality of a mouse. These let you push back from your desktop to browse digital photos while leaving your mouse on the desk yet still taking advantage of some of its functions.

The Logitech Cordless Desktop MX 5000 Laser keyboard uses a built-in LCD at the center top of its keyboard. This screen reflected the keyboard’s synching with my computer: it displayed my name, the date and the time. When I played music, the artist and song title scrolled across the screen. This could come in handy if you planned to constantly use the keyboard away from the PC. But in most cases, the content on the LCD wasn’t that helpful, and seemed repetitive of what was on the computer screen.

The Logitech mouse is sculpted to fit a hand and it offered more buttons for scrolling and navigation than the Microsoft set’s mouse. To recharge, this mouse fits upright in a stand. Microsoft’s wireless mouse recharges by lying flat on a recharging strip.

I used Microsoft’s Natural Ergonomic Keyboard 4000 with my desktop computers at work and in place of a small laptop’s squished keyboard. Its arched center and split keys took a little getting used to, but I was soon hooked. A special feature in the center of the keyboard called the Zoom Slider lets you zoom in or out to adjust the view of a screen. This worked for me in Microsoft Word documents, but not in Outlook Express or within Firefox’s browser.

Five large, numbered buttons at the center top of this ergo keyboard are called My Favorites, and I programmed them with ease by pressing one and entering the desired destination, including folders, browsers, or specific Web sites.

But typing on this keyboard really won me over. Its split setup won’t work for everyone, but for touch typists, it’s truly more comfortable. I typed away with ease using my right and left fingers, and keys felt closer together due to their inward-tilting shape. I noticed that I made fewer mistakes typing on this keyboard than on a regular keyboard.

If you spend a lot of time at a computer each day, you may want to consider one of these keyboards or keyboard sets for better ergonomics and production. It takes a little while to get used to using keyboard shortcuts for things like music and photos, but these can be real time-savers. Whatever you choose, know that there are other options out there beyond what came with your computer, and that they’re usually worth the extra money.

Edited by Walter S. Mossberg

• Email me at MossbergSolution@wsj.com. Find these columns online for free at the new All Things Digital Web site: solution.allthingsd.com.

But these wires aren’t just making a statement to techie trendsetters. Thieves have picked up on the fact that these white eye-catchers are attached to an iPod that costs anywhere from $99 to $449. New York City police have even attributed a recent rise in robberies on subways in part to iPod theft, noting that the white headphone wires are a major lure.

Today, Logitech International is introducing a new product that will eliminate the wires between your ears and your iPod, but it might not necessarily be less noticeable than white wires. The company’s $150 Wireless Headphones for iPod work using Bluetooth, a short-range radio technology that lets the iPod stream music to the headphones over the air, and allows the headphones to control song playback.

Such wireless headphones have long been a dream of hard-core iPod fanatics. And this product is one of the first of what could be a flood of wireless headphones for the iPod and other music devices, especially as the headphones’ prices and sizes decrease. Last year, Hewlett-Packard introduced its own $100 Bluetooth Stereo Headphones for its iPAQ PDA, which also plays music, and TEN Technology sells a $140 Bluetooth adapter for the iPod that enables HP’s wireless headphones to work with Apple’s player.

My assistant Katie Boehret and I have been testing Logitech’s new wireless headphones with a $299 20-gigabyte iPod and a $199 four-gigabyte iPod Mini (any iPod with a dock connector will work) to see how they work. We paid special attention to ease of use — after all, they’re still just headphones and shouldn’t be complicated. We also noted how comfortable they were. Consumers often buy alternate headphones for their iPods instead of using Apple’s standard white earbuds because the latter are uncomfortable after long-term use.

Overall, we found the Logitech headphones to be a mixed bag. Though they worked and allowed us more freedom when using the iPods, they were too expensive and, worse, they were bulky and uncomfortable.

The headphones themselves consist of two ear-covering, circular pieces that connect via a plastic band that wraps around the back of your head. The right earpiece has volume and playback controls for the iPod built onto it, positioned in a circular pattern similar to the buttons on an iPod wheel.

Two additional components come with the headphones and are necessary to use them: a Bluetooth receiver that attaches to the top of your iPod and a power adapter for charging the receiver’s and headphones’ internal batteries. Before testing, we charged the headphones and receiver by attaching them to the power adapter; both displayed an orange glowing light until charged, then the light went out. Logitech says one charge will last for eight hours; we got to nine hours before hitting an empty tank.

Logitech’s $149.99 Wireless Headphones for iPod (right), with its receiver (left) that connects to the iPod.

Most Bluetooth devices that we’ve used in the past required us to go through an arduously annoying “pairing” process, during which the Bluetooth receiver must find and recognize the device that it’s trying to “pair” with it. This process often involves entering a four-digit password on one or both devices and crossing your fingers in hopes that it will work.

We were pleasantly surprised that these headphones come pre-paired with their corresponding Bluetooth receiver, which makes setup as easy as turning on the two devices.

The white, rectangular receiver snaps into the headphone jack of an iPod. Our iPods turned on automatically when the receiver was inserted into each, in turn, and a light on the receiver blinked red, meaning it’s on but not connected to a Bluetooth device. (You can turn the iPod back off with the receiver still attached to save the battery when not in use.)

We pressed the center button on the headphones’ right earpiece. A small light on the earpiece started blinking blue, and the receiver’s light did the same, then turned solid blue, indicating that the two were paired. We pressed the center button on our headset again to play music, used two buttons to skip ahead and back through songs and pressed plus and minus buttons to adjust volume.

We donned the headphones, and our music sounded just like it would on wired headphones — various genres ranging from classical to country to rock were perfectly audible. It took only a few minutes to remember where each button was located on the earpiece without looking. Soon, we were up and walking around the office, enjoying our wire-free listening. Katie wandered about 15 feet from her iPod into my office — around a corner and through two doors — without losing the sound. She then wandered about another 15 feet farther down the hall to test the Bluetooth’s 30-foot range, which proved accurate. Just slightly beyond 30 feet, the music started to skip and sound shaky, but up until then, it still sounded fine.

But we were very disappointed by the discomfort of the headphones. They weigh only 3.2 ounces, but due to the behind-the-head design, each earpiece seemed very heavy. If the plastic connecting piece had been designed to go over the top of your head, it would have balanced the weight on each ear. Also, the headpiece doesn’t adjust to become smaller or larger. With the loose fit and the weight, the headphones kept sliding off when we walked briskly or jogged. Katie could barely keep the Wireless Headphones on for 45 minutes before taking them off because they were so uncomfortable.

The idea of using wireless headphones is a good one, and the Bluetooth connection worked as advertised. But we can’t justify the $150 price tag — almost as much as the low-end iPod mini — and the discomfort that come along with Logitech’s Wireless Headphones. We expect that other companies will introduce more comfortable wireless headphones so that all of us can eventually ditch our dangling ear accessories. But for now, keep detangling those wires until a better product comes along.

With reporting by Katherine Boehret

Write to Walter S. Mossberg at mossberg@wsj.com