With various rumour sites predicting a subnotebook Macintosh for weeks - and months in some cases - it didn't come as a surprise when Apple CEO Steve Jobs unveiled the company's new super-svelte laptop at his Macworld keynote last week.

That didn't stop the oohs and aahs the MacBook Air got from spectators on the Macworld show floor.

You can't argue that the MacBook Air is a superthin laptop or with Apple's claims that it is the thinnest laptop on the planet. It measures just 0.16 in. at one side and 0.76 in. at the other, but the pictures floating around the Web don't do justice to how thin and light Apple has made this machine. Even Apple's current line of superthin USB and Bluetooth keyboards look fat by comparison, and lifting a MacBook Air with one hand makes you realise that it weighs about as much as a small stack of paper plates.

Apple also included a mercury- and arsenic-free LED backlit display. The display packs a lot of brightness and clarity that really has to be seen to believed - it may be one of the best laptop displays ever created. Its immediate full brightness is a nice feature, though the real value comes in the power savings when compared with traditional laptop displays.

The display's environmentally friendly design addresses criticism that Apple has received from Greenpeace International and other environmental groups over the past year. Indeed, no Apple-made circuit boards in the MacBook Air contain polyvinyl chloride (PVC) or rely on brominated surfaces. The result: a laptop that's thin, light, bright and green.

In his speech, Jobs argued that Apple avoided some of the common concerns that go with ultraportable notebooks. The MacBook Air has a full-size keyboard that supports ambient light sensors and backlighting, the same 13.3-in. screen size used in the MacBook line, and low power to reduce heat and conserve juice.

But it does rely on slower processor options than the current generation of Apple laptops. In fact, it sports chips similar in speed to the original MacBook Pro configuration introduced two years ago.

But MacBook Air buyers aren't likely looking for speed alone, and it still packs more power than many other subnotebooks by using processors custom-designed for Apple by Intel Corp. Those chips - 1.6 GHz in stock configuration, 1.83 GHz on the top end - are fine for the most common tasks that users wanting an ultraportable Mac are likely to need.