But a much larger number of digital pictures -- between 70 billion and 100 billion, industry insiders estimate -- never made it to the printer. Consumers posted some of these images on Internet photo sharing sites such as Photobucket and Flickr, but most of the the files are now consigned to sit on memory cards or hard drives, where they will be viewed rarely, if ever. "There are so many images being captured now," observes Ed Lee, a digital photography analyst at InfoTrends. "Who can afford the time to look at them all?"

In my own experience, digital frames provide a convenient and unintrusive venue for these unprinted images. All of the frames use similar slide-show formats, with adjustable display times and transitions; once set to run, the frames can cycle through hundreds of pictures, including, perhaps, the occasional surprise photo you had entirely forgotten. If prices for frame continue to drop, it seems inevitable that they will become just as common a part of 21^st-century environments as the family photos on our desks at work and the wedding and vacation pictures hanging in our hallways at home.

Still, Lee is unconvinced that 2007 is the year for the takeoff of the digital photo frame. "The new frames do offer a different viewing experience, which is nice," he says. "But is the market going to really explode this year? I still have my reservations."

Despite improved connectivity, screen size, resolution, and storage capacity, digital frames still have a few serious limitations. For one thing, they must be connected at all times to an AC power outlet. "There is no way to run these frames constantly on batteries," says Lee. "In which case you are physically limited in where you can put these things." At CES, many vendors embedded their digital frames in the walls of their booths; unseen, of course, were the power cables snaking through these walls. The chances that the average frame buyer will hire the carpenters and electricians needed to install frames this way in their homes seem low.

In any case, the displays on these devices are still too small to be seen clearly across a room, meaning they're more appropriate for the coffee table than the conservatory walls. And consumers may also balk at spending $150 to $250 on a dedicated photo frame when they could put the money toward more other media devices that have reasonably-sized screens and greater versatility, such as laptops, Apple's coming iPhone (which doubles as a wide-screen video and photo viewer), and the new crop of ultra-portable PCs from Samsung, Sony, and Nokia. Dedicated frames will provide one more way to exhume old digital photos from their electronic shoeboxes - but frame makers will be lucky if the competition with computer and phone makers comes even close to a photo finish.