IBM ThinkPad's are also great laptops but you'll pay more.
Dell gives you better bang for your buck, but you may want to spring for the 3 year warranty.
IBM ThinkPad R31 for $679 brand new direct from IBM:
CPU: Intel Celeron-M 1.13GHz
128MB Included / 1GB Max.
Hard Drive2 20GB
Display 13.3" TFT 1024x768
Operating System3 Microsoft® Windows® XP Professional
Ethernet/Modem Ethernet & Modem Included
Media Device CD-ROM
Graphics chipset Intel 830MG Integrated
Travel Weight4 5.3lbs
Thinness5 1.42in
Limited Warranty period One year parts and labor (system battery: one year)
AC Adapter Included
Battery Included
RAM is cheap just wish it came with 256MB RAM and DVD-ROM but it's a good price for a solid brand new laptop.