I have a personal preference for ThinkPads, I have to admit. I love the keyboards and the pointer stick (I got really good at navigating on my old T40 with that stick!). But it died after 3 years - had to send it back to get it fixed - worked for about another 2 more months and then died for good (just fell out of warranty service). They're not made by IBM anymore, BTW - they're made by Lenovo. I ended up replacing it with a Dell laptop which also got replaced by another Dell laptop (my current 6000).
I've liked my Dell laptops but they've never been on the cutting edge of tech, that's for sure (except maybe for the XPS line). They're a great value fot the price though.
Panasonic Toughbooks are an interesting beast - I don't need a laptop that's built like a tank but someone that's accident-prone might like to have that security ... :)
Gateway and Toshiba are both decent companies - in the midprice range level, as Marc has said, all computers (including laptops) are commodities and very little is different from one laptop to another. For specialized needs though, the brand/design does make a difference ...
Doug - I love Powerbooks (Amanda has the titanium 15 inch PBook) but I'm assuming that Claudia's got an investment in software/data that she'd like to keep. If that's not true, the 12 inch PBooks would also be an excellent choice. Tiger is really a smart OS.
Joanna - Tony's my hero. :D
Masaki