Each of the major studios has agreed to provide movies for Apple's iTunes movie rental service, Apple chief Steve Jobs announced at the MacWorld conference in San Francisco Tuesday. The inclusion of Universal and Sony were major surprises since each had indicated it would launch a similar service. Moreover, Jobs said, the films could be downloaded and viewed on ordinary or high-definition TV sets via Apple's settop box -- without the use of a computer. They would rent for $2.99 for older titles, $3.99 for newer ones -- although "newer" is relative. Films will not become available on iTunes until at least 30 days after they are released on DVD. HD movies will cost $1.00 more than conventional ones to rent. Analysts pointed to other drawbacks: films can only be viewed for 24 hours -- fine for home viewing but annoying for those downloading them onto iPods and iPhones for viewing in increments during their commutes, lunch breaks, or work-outs. Moreover, only about 1,000 movies will be available when Apple's video-rental store opens online in February. Nevertheless, Apple's maneuver received mostly positive response from analysts and newspaper critics. Commented the London Times: "Apple's move into video rentals, if successful, is likely to change fundamentally the economics of the film industry, and provoke yet more arguments over the way internet royalties are paid to writers." Also on Tuesday, Jobs unveiled a new, thin laptop computer, the MacBook Air -- so thin that it does not sport a slot for playing DVDs.