Two weeks ago, I talked about ABC TV's decision to air the most recent episodes of hit TV shows such as Alias and Lost on its Web site. The idea behind the move was that viewers who missed an individual episode could tune in through the Web within a week to catch up on the show. Starting Monday, ABC's new service has become available, so now we're ready to gauge its quality and convenience. Put simply, it's not horrible.

The big problem, of course, is that you must be online to view the shows as they stream through a small window in a Web browser. No download options are available. I can see watching a TV show on a laptop, perhaps while traveling, but I wouldn't typically tune in on my desktop PC, which has a large widescreen display.

Another problem is advertising. The Web-based ABC shows include advertising, much like the TV-based originals. Although you can pause, rewind, and fast-forward during the actual TV episodes, you can't fast-forward through commercials. So, as with TV, you'll have to suffer through them or get up and do something else for a bit.

Quality is surprisingly good, but you'll still see the artifacting and blurriness that often accompany the heavily compressed videos we've come to expect from PCs. If you've ever downloaded a TV show from iTunes, the comparison is interesting: The Web-based ABC shows offer higher resolution than their iTunes equivalents and are shown in the correct aspect ratio. For example, on iTunes, Lost is shown in at 320 x 240 and is inexplicably cropped into a 4:3 aspect ratio. But Lost is actually recorded in widescreen, and the Web-based version retains the correct aspect ratio with a resolution of 500 x 282. It's significantly better than what you get on iTunes.

The iTunes version of a Lost episode will set you back $1.99. For that price, you can bring the episode with you and watch it offline on as many as five PCs (or Macs) and can even watch it on the tiny screen of the latest iPod if you don't mind the eye strain (and the fact that videos drain an iPod battery at an alarming rate). Also, there are no commercials in the iTunes version, which is obviously a huge benefit.

People who wait for the DVD set of Lost Season 2, or other TV shows, will benefit enormously in price, quality, and extra features when compared to iTunes downloads. They'll also get a version of the show that is infinitely more accessible than the Web episodes. Plus, there's the benefit of being able to enjoy an entire season's worth of shows in large chunks.

To be fair, ABC isn't trying to compete with DVDs or even iTunes. The goal here is to let real fans have another option if they miss a single episode. It's a wonderful gesture, and although I'd like to see at least a download option, if not a full-resolution version, it's a good start. The future of video is on-demand. It's nice to see that ABC gets that.