Apple chief executive Steve Jobs unveiled the latest incarnation of his company's signature iMac desktop computer on Tuesday.

The new iMac models feature a brushed aluminum casing similar to that of the Mac Pro tower, combined with a glossy black encircling the LCD display.

As was rumoured last week, the revamped iMac also includes a newly designed keyboard. The compact keyboard features white keys on a thin aluminum sheet and is roughly one third of an inch thick. The new machines will also have a small door on the bottom to simplify RAM upgrades.

The choice of aluminum and glass wasn't purely a design issue. Jobs said that both materials were also used because they are "highly desirable" to recyclers. In recent months Apple has taken criticism from Greenpeace, which claimed that the company's recycling efforts are lacking.

Only two sizes of the iMac will be offered; a 20-inch model and a 24-inch model, which will sell at $1,499 and $1,799 respectively. Apple has discontined its 17-inch iMac.

Once considered to be the company's flagship product, laptops have taken over the iMac's position as the best selling product, accounting for two thirds of all Mac sales. Still, Jobs remained optimistic that the iMac's compact all-in-one design will allow it to fare better than tower desktop PCs.

"We often ask ourselves why people still put up with this kind of stuff," Jobs said, during the unveiling at the firm's corporate headquarters, pointing to an image of a Dell desktop.

"We think it's an all-in-one world."

The CEO again ripped rival vendors when asked about the iMac's relatively high price tag in comparison with other consumer PCs.

"We make products that we are proud to sell and we sell them for the lowest price we can. We don't offer stripped down, lousy products," he declared.

"There is some stuff in our industry that we would not be proud to sell."