Best Laptop for $600 max

Hello fellow Vergians. Vergers. Whatever.

My mom's trusted old Thinkpad T41p running Ubuntu Linux recently went off the deep end. She's now looking to buy a new laptop and has asked me for help. Little does she know that since buying my MBP last year, I haven't been keeping up with what's good. Her budget is around $600. She's not looking for anything too far out there, but it should be mobile and compact. A nice display would be good as well, as she mostly surfs the web, reads a lot and does her email. Also the Thinkpad's screen was a pain in the ass. She's looking to upgrade a little.

If you've got any good suggestions for me, you'd be making one guy's mom extremely happy. (That just sounded weird.)

Thanks!