I have to chime in with a hearty iBook recommendation as well, based on your needs and your budget. A fine computer. My best friend has the 14" model (the first generation of G4 iBooks from last autumn...1GHz, 40GB, etc.) and she loves everything about it. In fact, she got an AirPort Express just last weekend and now she loves it even MORE! But if you crave portability in a tough, nice-looking package...there's your computer.
The iBooks are great. And I hear there's a spanning hack too...