Small and light

For my travelling I need a 12" laptop. It doesn't have to be thin but it needs to be lighter than the iBook. With a hand luggage weight limit of 5kg, 2.26kg (5lb) is too heavy. I need a 320GB Hard Drive and all the usual ports (Ethernet, USB2, Firewire) and wireless. Such a beast doesn't exist in Apple's line-up at any price, so I won't be "upgrading" any time soon. I love OSX but there's a distinct lack of choice in hardware.