There is a users group for running Wacom tablets under Linux. I understand that they're fairly responsive, but I haven't started experimenting with Linux yet, so I don't have any first-hand knowledge about it. Wacom itself provides no Linux support.

Since we're on the topic, if you use a tablet under Vista, I recommend uninstalling (or at least turning off) Windows' Tablet PC utility. It conflicted with my Intuous3 driver, randomly turning off pressure sensitivity in Photoshop and preventing me from mapping the drawing surface to a single screen.