Good advice so far -
don't get a laptop unless you NEED a laptop, right now. IMHO, Apple makes the best laptops out there today, and the only ones I'd spend my own money on, given any choice at all - great battery life, everything integrated, great software, but many prefer Windows.
My experience, however, is that Windows laptops do really poorly over time - they're highly integrated packages, and when you upgrade the OS, it's often a bit rough from then on.
IBM makes great laptops, but you pay for it. Dell makes pretty good laptops most of the time (there are a few real problem children), and you get more than you paid for. Huge fan of their 'Complete Care' all-hazards warranty.
You couldn't get me to take an HP, Compaq, Toshiba or Sony for free, much less with personal money. I'm sure someone has had a good experience with these brands, but mine points me away.
I'd buy Apple first, IBM with someone else's money, and Dell Latitude if I needed to buy a Windows laptop with my own $$.
Finally, I'll say that I really like smaller machines - if you really NEED a portable machine, having it be small enough to carry easily is a HUGE plus. 6lbs is my absolute top end, and I love my 12" powerbook at 4.6lbs.