The Fujitsu Lifebook S6220 is a pretty sweet machine. It can get 8.5 hours of battery life with the modular-bay battery, which of course will cost you a little extra. The S6220 has the Dothan 735 (1.7Ghz), which is the biggest difference between it and the S6210, which you can still buy with Banias processors if you're looking to save a little money.
Lots of people like the S7000 series, but I wouldn't pick it because unlike the S6000 series, it doesn't have a CrystalView screen (it's just a brand name for Fujitsu's best TFT screen). Both the S7000 and S6000 series come in XGA resolution; the S6000 series is a little smaller, at a 13.3" resolution, which works great at that size. A friend has one, and it's a beautiful machine. I'm recommending it because it's got great performance (with the only drawback being integrated graphics), it's light-weight at well under 4 pounds with a single battery, it's stylish, and it's the perfect size for a student. Get yourself something like that with a notebook sleeve, and you can tuck it in your bookbag with no problems, or tote it under your arm without the power adapter all day.
If you do go with a Fujitsu, I'd check out portableone.com; they're Fujitsu resellers that also provide support in the States. Their prices on RAM and other upgrades are reasonable, and you can also order the machine from them with better hard drives-- I think they've got the 7K60 and 5K80 available at time of order, something not offered on Fujitsu's website.