I have an old Acer and so does my roommate and they've both broken more than once and Acer wouldn't help us, so I would advice from experience against them. Since you are going to school for programming I would recommend getting a decent computer. You should have at least 1GB or RAM and an Intel Dual Core processor. Since you are planning to use Linux then I would buy a blank one (part of the price that you pay in the store is for the operating system.)

I'm not sure about you school but mine has been quickly transfering its computer departments to Macs since they've gone to intel processors. They will run almost any operating system (including Ubuntu), but are high end and expensive. My school uses Suns for all of the networking courses, but I'm not sure if they make laptops.

You mentioned that you like Python, most of your early classes will be probably either Java or C.

From what I've encountered the most reliable companies for computers are IBM, Apple, and Dell. If you're computer science (I assumed that you were) then it would be worth it to get a high end computer so that you can use it for all four years.