Apple Chief Executive Steve Jobs takes the stage today at the Macworld Expo in San Francisco where many are expecting him to unveil the company's smallest notebook computer ever.

Rumors about the mystery product have been intensifying ahead of the show. The computer would be an ultra-light sub-notebook, weighing less than 4 pounds and 1 inch thick.

The current line of Apple notebooks runs on Intel processors, offering the consumer oriented MacBook and the more expensive MacBook Pro.

The current MacBook weighs 5 pounds and is 1.08 inches high starts at about $1,500. The MacBook Pro is a little heftier at 5.4 pounds but shorter at a 1 inch height. It starts at $2,000. Sub-notebooks are typically under 4 lbs and are less than 1 inch thick. They are also typically more expensive.

Rumors ahead of Macworld are calling the potential notebook the MacBook Air.

Analysts have also weighed in with the size of the notebook's screen ranging between 11 and 13 inches. Other potential features include a flash memory hard-drive, which would replace the traditional mechanical version.

See full coverage from Macworld 2008