I got a 12" iBook. It does every thing I want it to do while I'm away. Plays DVDs (all regions too), got a WiFi card in it too. I've got some games on it and I can tap out a few word docs too.
It weighs 2.1kg and it is quite strong too. It's quite up to taking a few bumps.
The iBook's had a spec upgrade since I bought this one so if you can, look for a 800Mhz chip if you want a bargain but do check out the 1Ghz chip specs so you know what you're getting.