Bamboo Tablet Custom Photoshop Buttons?

I recently acquired a Wacom Bamboo Pen&Touch, and I love it. I'm pretty sure it's possible to assign custom actions to the buttons on the pen specifically for Photoshop, and I've done some hunting, but I can't find anything that documents how to do it.

I've got PS CS3 Extended, running 10.6.3 and a brand new Pen&Touch.

I'm sure there's an easy answer to this, but I'd really appreciate some help as I'm baffled at this point.