I have two Bamboo tablets, the older one is attached to my work PC, and the newer one (with wireless accessories) lives at home. In both cases, I've disabled the tablet buttons entirely, as I ended up brushing against them by accident far more often than actually using them. For the pen buttons, the first one is set to act as the Ctrl modifier, mainly for use in Paint Shop Pro where Ctrl-clicking picks up a color under the cursor. The second button is set to Ctrl-Z (Undo).

-- Ben