Apple has launched the iBook, a funky laptop computer it hopes can repeat the enormous success of its iMac desktop machine.

The iBook is "the 'iMac to Go' for both home and school," said interim Apple chief executive officer Steve Jobs, unveiling the portable at the MacWorld Expo trade show in New York.

The iBook's other antecedent is the eMate - a smaller, clam-shaped portable that was aimed at schoolchildren. The new machine will cost $1,599 (around £1,000) and should go on sale in the US and UK in September.

Airport gives wireless Net connection

The iBook's most innovative features are its casing - translucent, in Blueberry or Tangerine, and with a pull-out handle and rubber coating for durability - and its Airport wireless networking (a $400 extra).

Available in Tangerine and Blueberry

Airport consists of a card in the iBook that communicates with a base station similar to that of a cordless phone. It means you can be connected to the Internet from anywhere in the home without the need for wires and a phone point nearby.

Data rate is up to 11mb/sec and range is more than 40 metres. And with more than one iBook in the family, multi-player gaming over the wireless network is possible as well as shared Internet connections.

iBook is no lightweight

The iBook also features a 30.7-cm (12.1 inch) colour screen, 56K modem, 3.2GB hard drive, 32Mb of memory, CD-Rom drive and a 300MHz PowerPC G3 processor that Apple claims will outperform the fastest Intel processor found in any notebook PC.

But the iBook, like the iMac, does not have a floppy drive and it weighs a sizeable 3kg (6.7 pounds).