Ditto what gberardi said! Especially considering Ubuntu. I have no idea how complicated other Linux systems are, but I loooove Ubuntu.
And my only suggestion would be to give away zillions of those nifty
"Powered by Ubuntu" stickers. After going through hell putting Xubuntu on an old laptop with no onboard CD or floppy drives or bootable USB support, I peeled that "Designed for Windows" sticker right off and replaced it with my Ubuntu sticker. Hell yeah!