Amazon launched its own video download service on Thursday called Unbox. The service features DVD-quality movies and TV shows from over 30 studio and network partners. Downloaded videos also include a second file optimized for playback on handheld multimedia devices.

Unbox uses a progressive download system that lets viewers begin watching shows while they are downloading, instead of making them wait until the entire file has been saved to their hard drive. This means that customers with a typical DLS or cable modem connection can start watching a show within about five minutes or purchase.

Amazon Unbox

TV shows are priced at US$1.99 each, and most movies are priced between $7.99 and $14.99. Movie rentals are also available for $3.99. A rental is valid for 30 days, and automatically disables itself 24 hours after you watch it.

The service also includes Amazon Your Media Library, a Web-based service that tracks your Amazon media purchases. From here, users can track their Unbox purchases and download them to an additional computer.

For all of its features, Unbox does have limitations: All of the videos are encoded with Microsoft's digital rights management technology, which prohibits playback on the Mac or iPod. The Unbox video player software requires Windows XP, and you can't burn DVD player-compatible discs.

Amazon's Unbox beats Apple to the punch by almost a week. Analysts expect Apple is announcing its own movie download service on Tuesday, September 12 at its "Showtime" media event.

Reports currently indicate that Apple is launching its service only with Disney and its affiliate studios, which are missing from Amazon's Unbox. Lionsgate, however, indicated during an investors conference call that it has signed on with Apple as well.