Apple Inc CEO Steve Jobs unveiled the Macbook Air , a 3-pound uber-thin notebook PC that fits inside an interoffice envelope. He also said iTunes is now offering online movie rentals, conceding that at least so far, neither Apple nor any other company has yet to come up a service that consumers are flocking to.

Both of the announcements had been expected, and investors sent shares of Apple down more than 5 percent during and after Jobs’ keynote presentation. There was no iPhone announcement at this year’s Macworld, though Jobs unveiled a software update to the iPhone that enables on-the-go locations while using the phone’s map function. He also said that the company has so far sold more than 4 million iPhone smartphones.

Spotted milling about this year at Macworld: Google Inc co-founder Sergey Brin, Google CEO Eric Schmidt and San Francisco Mayor Gavin Newsom. Academy-award and Grammy-award winner Randy Newman, who scored music for some Pixar films, came on stage at the end and performed a couple of songs.