Graphics Tablets And Linux?

Forkenhoppen asks: "What is graphic tablet support like under Linux? I'm interested in getting a tablet for my computer for drawing/touching up art, and for using with the Gimp. What have people's past experiences been with different types of graphics tablets? What is the best one? Is there a low-cost tablet that works well under Linux? Are USB tablets supported? And most importantly, how many people actually use graphics tablets under Linux?"