Steve Jobs announced iTunes Movie Rentals today during his Macworld San Francisco 2008 keynote address.

Apple has partnered with Touchstone, Mirimax, Lionsgate, Newline, Fox, MGM, Warner Bros., Disney, Paramount, Sony and Universal to bring movie rentals to Macs, PCs, iPods, iPhones, and Apple TVs through the iTunes Store. Rentals go for $2.99 for current/older movies and $3.99 for new releases at DVD quality. 1000 movies are available at launch in this format. Rented movies will be available 30 days after the DVD release of a film and a user has 30 days in which to start watching the film and 24 hours to complete the viewing once started. With a broadband connection, there is only a 30 second lag before viewing can begin once purchased.

High definition movies are also available for $4.99 each, with 100 titles available today -- but it appears these are only available on the Apple TV.

Speaking of the Apple TV, a massive update to the Apple TV's system software was shown at today's keynote. A free software update will be available to Apple TV owners in two weeks which allows access to the iTunes Store's new rental features. With this update, movies can be previewed and purchased through the new interface, photo screensavers can be retrieved from .Mac web galleries, and music can be purchased from the iTunes Store. What's more, the Apple TV device has been reduced in price from $299 to $229.

Jobs indicated that as of last week over four billion songs had been sold through the iTunes Store. The single-day record for sales was Christmas Day 2007 when 20 million songs were sold in a 24 hour span of time.