I'd like to add that I've used Dell's cheapy servers for years at home and have never had any problems with their Linux support. Well put together and quiet, too.
I run linux on my Latitude E6500 (and it runs just as well on the E6510) and it works out of the box.Those are well outside the $1000 budget that was first stated, but linux runs great on any and all the Dell laptops I've ever used. I only listed their ubuntu page because it's a linux offering.I know that Dell also sells "no os" or freeDOS machines too but I didn't see any laptops on their site. You could always go through the Dell outlet and buy from there and the discount would put you under or near the $1000 mark.Regardless, the Dell Latitude line work great as a linux laptop.