I had an old laptop that was chugging under XP and I was half thinking of using it for a future desktop fab project. A friend suggested and supplied a Ubuntu installation CD, which installed without hassle (I don't really have any Linux experience). It detected my Wi-Fi network and connected remarkably easily too (better than Windows). I've not had chance to look at it any closer yet.
I've also taken another old laptop off the hands of a colleague, "free to a good home" and it's running XP fairly well. It came with working wireless and I'm thinking of maybe turning it into a large digital picture frame.
So many projects, so little time...