Visiting YouTube for a test-drive yields an unimaginable wealth of - well, I don't really know what you'd call it. A lot of video clips. I even conducted a test of random, obscure searches, just to see what was in the archive. If you want to stump the system, you'll have to try harder than I did.

A search for Homer Simpson's favorite '70s rock band, "Bachman-Turner Overdrive," brings up 13 videos. (Were there even 13 videos made of the band?) There are 94 clips for "Donald Rumsfeld." "The Brady Bunch theme song" - 15 clips. The 1960s Brazilian Tropicália group "Os Mutantes" brings up 60. Taking a cue from YouTube cofounder Chen, I search for "cat tricks" and come up with 374. How about something nonsensical, like "monkey peanut butter"? Voilà, two very-good-quality clips of monkeys eating peanut butter. And just for fun, searching for "NBC," one of YouTube's newest financial backers, yields 2,588 videos.

Yet for all the excitement, it's important to remember that online video is still a ­nascent media form. Picture quality is often grainy and not appropriate for a big-screen monitor. There's also the issue of profitability.­ YouTube has begun to run advertising on the site, but it will be a while before it generates enough revenue to be self-supporting.

And there's the problem of being the first. Online communities like Friendster and Napster captured our imagination not so long ago, but users have moved on. Although the equivalent of roughly a tenth of the U.S. population visits YouTube each month, competitors are already popping up. Internet ­giants Yahoo! and Google are offering free videos, as are a handful of start-ups like Revver, which offers cash to clip contributors. As for how long YouTube will maintain the dominant market share, no one knows.