Most users know how to upload photos, but don’t want to hassle with USB cords and slow upload speeds when transferring images onto a computer or photo-sharing site. Camera docks and memory-card readers built into PCs have attempted to alleviate these transferring problems, but these so-called shortcuts still require a certain amount of dedication to the process.

In the past couple of years, a handful of companies have gone a step farther by introducing Wi-Fi enabled digital cameras, notably Nikon Inc. and Eastman Kodak Co. But this capability works only in certain cameras and even then requires users to walk through a number of steps to send the photos through a service created by the company instead of sending them to a computer or Web site.

Little Effort Needed

This week, I tested a refreshingly simple gadget that solves this problem and does what most technology products don’t: It works in existing devices and requires next to no effort. The $100 Eye-Fi Card by Eye-Fi Inc. (www.eye.fi) is a two-gigabyte SecureDigital memory card with a built-in wireless chip. It slips into any camera with an SD-card slot, and whenever the camera is turned on, looks for a familiar Wi-Fi network and uploads your photos to your Mac or PC and one of 17 photo-sharing sites. After a quick, one-time setup, the user does nothing more than turning on the digital camera.

I thought this thing was too good to be true and set out to find its flaws. But after using it with two digital cameras (one brand new and the other over three years old), three different computers (each with different operating systems) and five photo-sharing sites, I’m convinced that the Eye-Fi is a terrific little tool. It works quickly and is a no-brainer to get going. The only people who won’t like it are those who enjoy razzing their lazy friends for forgetting to share digital photos.

Minor Inconveniences

The Eye-Fi’s flaws are minor enough to dismiss. For one thing, it doesn’t work on Wi-Fi networks that use log-in pages like those in Starbucks; instead, it’s meant to work on home networks or other “open” networks. Secondly, there’s no way to know when Eye-Fi finishes transferring photos unless you check your computer. Finally, your digital camera must stay on for the duration of the wireless transfer, which slightly taxes battery power, and slower networks and/or transferring numerous higher-resolution photos will require a bit more juice. Likewise, Eye-Fi looks for Wi-Fi networks whenever the camera is on, though the company says this only uses a minimal amount of the camera’s battery power.

The Eye-Fi Card comes in a small, colorful box that reminded me of a pop-up book: Pull one side and a quick-start guide appears on the right while the left swings out a piece holding the Eye-Fi card reader and SD card. This reader is only needed for the initial setup on each computer, which only took a few minutes per system.

I tried my Eye-Fi first on a Windows XP machine, plugging the card reader and card into a USB port. The software setup walks users through clear, quick steps like testing the computer’s firewall to be sure it can work through it and asking which folder should be designated to receive wirelessly transferred images. Here, I also typed in my account information for sharing images on Kodak Gallery; later I added Shutterfly, Snapfish, Picasa and Flickr. Other online destinations included blogs like Vox and TypePad, along with social-networking giant Facebook. The last step instructed me to insert the Eye-Fi SD card into my camera to snap the first test photo of myself, making sure it was working properly.

Managing Your Photos

Transferred photos are all reflected in the Eye-Fi Manager, a Web-based, password-protected site that tells which images were uploaded to photo-sharing sites and the computer. Users can opt to only upload from the Eye-Fi to one or the other or both, but only one photo-sharing site and one Mac or PC can be selected at a time. Account information for any of the 17 sharing sites can be saved within Eye-Fi, making it a cinch to switch where you want to send photos.

Around the office, within my registered Wi-Fi network, I took photos that showed up seconds later on my computer screen. At home, I entered my password-protected network’s information one time and watched as captured photos transferred wirelessly from my camera to either my Mac or Windows Vista laptop.

Quick Transfers

On average, it took about 40 seconds to upload each image to a Web site and about 40 seconds more after that for a photo to transfer onto my hard drive. I got home from a friend’s cocktail party and set my camera on a table with its power on. Ten minutes later, I turned on my computer to check the transfer and 12 photos from the party were uploaded to my Kodak Gallery account and my iMac’s hard drive.

Images upload in JPEG formats using their original, full resolutions. Some sharing sites change the formats for photos, but this varies between sites and isn’t related to Eye-Fi.

Eye-Fi won’t do absolutely everything for you, so for certain photo-sharing sites, you’ll still need to log on to send out emails for sharing albums with friends. But double clicking on any of the images in the Eye-Fi Manager takes you directly to wherever that image lives — whether on Picasa, Flickr, or your own hard drive.

I swapped the Eye-Fi SD card from one camera, an older Konica-Minolta Dimage X50 that still works well, to a new Kodak EasyShare V1253, which ironically has built-in photo emailing capability that isn’t nearly as easy to use as Eye-Fi. The Eye-Fi didn’t miss a beat and operated the same way in both cameras.

The Eye-Fi Card is as simple as it sounds and works with most cameras that use SD cards (for a complete list of compatible cameras, see http://support.eye.fi/compatibility/). If someone you know is constantly taking pictures that are never seen again by anyone else and they use a Wi-Fi network, Eye-Fi will serve as a carefree solution that takes the aggravation out of transferring photos to share with others.

Edited By Walter S. Mossberg

• Email mossbergsolution@wsj.com

And the camera makers keep turning out attractive new pocket digital models. Over this past Memorial Day weekend, my assistant Katie Boehret and I tested five of the newest pocket digital cameras from Nikon, Fujifilm, Kodak, Canon and Konica Minolta. These cameras range in price from $349 to $499; all weigh six ounces or less, not counting their batteries; and all are an inch or less thick. (Except for the Konica Minolta and Canon, these are official list prices; buyers may be able to find the cameras for less.)

Each of these cameras has a maximum resolution of about five megapixels, except for the Canon, which is $100 more than any of the others, and can capture up to 7.1-megapixel images. Unless you do very heavy editing of photos, or make prints larger than 8×10’s, five megapixels is more than enough for any casual photographer.

Zooming In

They all have the capability to record short video clips. And all have 3x optical zoom, which is sufficient for casual shooters. But only two of the five cameras — the Kodak and Canon — have lenses that physically protrude from the camera body. The others use internal zooming technology, which means that the camera face always remains flat, even when completely zoomed in on an object. All five use proprietary batteries and seemed able to sustain an average day of shooting.

Four of the five models, all except the Canon, have huge, 2.5-inch LCD screens on the back, up from the 2-inch or smaller screens common in pocket cameras only a year ago. But, to make room for the bigger screens, three of the five have omitted an essential feature, the optical viewfinder, which is a far better tool for framing a shot than the screen is.

Only the Canon and the Kodak have optical viewfinders. That means you can easily frame shots even when bright sunlight washes out the LCD screen, and your shots can be steadier than when you rely on the screen alone, which requires you to extend the camera away from your body.

In our tests, all of these cameras took rich, sharp pictures, indoors and out. You wouldn’t go wrong with any of them. But, because I consider optical viewfinders so important, I recommend the Canon or the Kodak. And of those two I lean toward the Kodak because it is $100 less, is thinner and lighter, and manages to combine both an optical viewfinder and the larger 2.5-inch screen. The Konica Minolta, which I have recommended in the past, is no longer my favorite because it has lost its optical viewfinder in its latest iteration.

Fujifilm FinePix Z1 List price: $399.95

The Kodak also benefits from being able to dock with the company’s snapshot printers and with nonprinting docks that work with Kodak’s EasyShare software to allow users to easily share pictures via email on a PC or Mac.

We should note that the Kodak that we tried out was a preproduction unit. In our tests, it was slower than the other cameras to ready itself to take the next shot. By contrast, the Canon seemed the fastest at shot-to-shot speed. But Kodak claims that the shot-to shot speed is much faster in production units.

The $400 Fujifilm FinePix Z1 caught our attention because of its sexy appearance. Instead of taking on the typical look of a digital camera, the front of the FinePix Z1 looks (in its closed state) like a simple black rectangle with silver-accented buttons and edges. A thin piece that covers the entire front side of the camera slides across to reveal the camera’s lens and flash, while simultaneously turning the camera on.

The Z1 measures just 0.7-inch wide, making it the slimmest of the five cameras that we tested. A generously sized 2.5-inch LCD viewing screen takes up most of the back side of the camera, but it lacks an optical viewfinder.

Focus Alert

Nikon Coolpix S1 List price: $379.95

We snapped photographs using the Z1 and found a few helpful features. An indicator lamp directly to the right of the LCD viewing screen blinked green when we held the shutter button halfway down, and then glowed steadily once the image was in focus, so we knew when to take the picture. The FinePix Z1 also is one of three cameras we reviewed that comes with a handy docking cradle for charging the camera’s battery and transferring its photos onto your computer.

The $380 Nikon Coolpix S1 also comes with a docking cradle, and it, too, earns points for its stylishly sleek appearance. Its most striking feature is how quietly it operates. When we pressed this silver camera’s “On/Off” button, a small metal circle instantly and almost noiselessly moved, revealing the camera’s lens like something out of a James Bond movie.

Lighten Up

When using the Nikon, we especially liked a feature built into the camera called D-Lighting, which allowed us to improve the lighting of a photograph after it was captured. We simply pressed the “OK” button while reviewing a captured image, and two small shots appeared on the screen — one that showed the image as it was, and one that showed how it would look after D-Lighting brightened the image, thus allowing us to choose to lighten it or not. We found that most of our pictures benefited from this in-camera editing process, especially shots that were taken indoors.

The buttons on the back of the Nikon proved a bit tough to operate. In keeping with the coolness of the camera, the Menu, Playback and Delete buttons are all tiny, smooth circles. But we found ourselves pushing them extra hard to get results, which was annoying. The Nikon lacks an optical viewfinder, forcing users to rely solely on its LCD screen for capturing photos.

Canon PowerShot SD500 Estimated street price: $499

The chunkiest of the cameras that we tested was the $500 Canon PowerShot SD500. But even though it weighed the most and was thicker than the rest that we tested, the SD500 is still a rather compact pocket camera.

We were impressed by the Canon’s quick start-up time, which seemed to be almost as fast as the 0.5-second start-up time of the Konica Minolta Dimage X60. And its mode dial — which many other Canon cameras also have — helps users easily switch between playback, video camera and photography modes.

The Canon offers a way to adjust color tones in photos by using a My Colors mode that allows you, for instance, to turn grass red or blue. But this seemed more of a gimmick than the Nikon’s genuinely useful D-Lighting feature.

And, unlike the stealthily quiet Nikon, the Canon seems to announce its presence with noise — its zoom lens whirs as it moves in and out, and special “click” sound effects can be heard whenever you take a picture.

The $400 Kodak EasyShare V550 combines its large screen and optical viewfinder in a slim, black matte body that has etched buttons on the top that light up blue, like the metal keypad on the iconic Motorola Razr cellphone.

Kodak EasyShare V550 List price: $399.95

It’s laced with touches of Kodak’s user-friendly approach, which we liked, including a blurry-picture alert and explanations of what picture-capturing mode you’re currently using (i.e. “Auto — use for general picture taking”). This camera also comes with a dock for charging the camera and transferring photos. This camera’s control buttons flank the left and right sides of its large LCD screen, and the optical viewfinder is oddly situated on the left side, which took a little getting used to.

Taking pictures with the Kodak was easy, and we liked the view screen better than any of the others, because it showed very rich colors. You can adjust the screen’s brightness by simply pressing the left or right arrows.

The last camera that we tested was the $350 Konica Minolta Dimage X60, the follow-up camera to the company’s Dimage X50, which is one of mine and Katie’s favorite digital cameras. The X50 had a 2-inch viewing screen, but still had an optical viewfinder. This new X60 has a 2.5-inch LCD screen but is the first Dimage X model we tested that ditches the viewfinder.

Trade-Offs

Konica Minolta Dimage X60 Estimated street price: $349.99

The Dimage X60 still has the same simple user interface that made its predecessor so popular, but because of the larger viewing screen, its buttons are much tinier. Its super-fast start-up time is a real boon for those who want to capture an image quickly. But, without the viewfinder, it’s no longer our top pick.

Overall, the quality of the images from all five cameras was impressive. Most of the colors seemed true to the actual subject, though the Konica Minolta’s images tended to have slightly rosier hues, which showed up in skin tones, and the Nikon had a somewhat yellow tint in some of our shots.

The Canon and Konica Minolta seemed to start up almost instantly, while the other cameras were a little more sluggish. But the shot-to-shot time for the Canon and Fujifilm cameras seemed to be the fastest overall.

There’s plenty to choose from in this crop of new pocket cameras, depending on your budget, tastes and needs. But the Kodak EasyShare V550 and the Canon PowerShot SD500 are the best of this lot, all in all.

With reporting by Katherine Boehret

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