Online video: The long and short of it

It starts innocently enough. You visit YouTube for, say, a few minutes of football bloopers. Then you switch to funny dog antics, followed by goofy juvenile stuntmen. Before long you've inadvertently spent 30 minutes watching videos on your computer.

Thirty minutes is the length of a TV show -- but would you sit down in front of your computer with the intent of watching a sitcom online? Or would you just go watch regular TV instead?

Much rides on that question, and a lot of smart money is betting you'll watch not only 30-minute shows online, but films and documentaries that last hours.

Prominent among that smart money is Joost. The online video service, currently being beta-tested, is from the same guys behind Skype. Like regular television, Joost is supported by advertising and boasts professionally produced content from major studios. It's full-screen video, too, like real TV.

It differs from TV in how the video gets to you: instead of broadcast, cable or satellite delivery, it's transmitted through the Internet via peer-to-peer technology. But while there are interactive features, like the ability to text-chat on-screen during a show, the overall experience is more or less like regular TV -- passive.

Joost isn't alone. Babelgum, VeohTV and others are also bringing the TV experience to your computer. While Joost seeks partners such as Viacom and CNN, Babelgum wants independent producers so it can offer, as its slogan boasts, "TV experience, Internet substance."

But will these services catch on? And if they do, will users abandon YouTube for more professionally produced content?