And you can get an Ubuntu machine from Dell that is very well supported.
I wouldn't recommend it to my parents, just yet (they're happy with OSX), but I wouldn't hesitate to recommend Dell+Ubuntu to people here. It might not be as sexy, but it's a setup that works pretty well. I had a tibook a number of years ago, and while it was certainly a beautiful machine that got lots of looks, in the end, I'm just as happy with my ugly clunky (but cheap and well supported) Dell.