Amazon just launched an for the Xbox 360, following the launch of a PS3 app in April. The new Xbox 360 app lets users watch more than 17,000 movies and TV episodes through the game console, and provides access to any videos purchased or rented through Amazon.com. It also supports Kinect for voice and motion controls.

Strangely, the Xbox 360 app does not allow users to buy a la carte videos directly through the game console. Instead, users must make the purchase through a Web browser on another device, and the video then appears automatically in the app's "video library" section.

For Amazon, the new app is a boost to its $79-per-year Prime service, which includes streaming videos, free two-day shipping on Amazon.com purchases, and a selection of free e-book rentals on Amazon's Kindle e-readers or Kindle Fire tablet. Amazon Prime Instant Video still lacks support for Nintendo's Wii and for smartphones and tablets (besides Amazon's Kindle Fire), so it's not totally ready to , but those extra Prime perks help the service stand out from its rival.

Microsoft, meanwhile, isn't picking winners and losers with its . The Xbox 360 also offers on-demand video apps from CinemaNow, Crackle, and Vudu, along with Microsoft's own Zune Marketplace, so there's plenty of competition between video services on the console.

We may see Microsoft make some more entertainment-related moves with Xbox during next week's E3 trade show. "Moving forward, Xbox will go beyond the box to reach all new families of devices," Yusuf Mehdi, Chief Marketing Officer for Microsoft's Interactive Entertainment Division, said in . "Just as Xbox has grown to mean more than just games, it also is more than just a console."