Okay, I'm back. Here's a side project I've been working on recently:

What's that, a ripped up Rock Band drum kit? Yep, sure is. I left the green pad on, because by the time I had figured out how to remove the pads, it was apparent that I didn't actually need the green one removed in order to remove the part I wanted:

Yep, that's some cutouts from the middle two drums (it's a separate piece of plastic that's in those two only), plus the main controller board upon which rests the normal buttons, though those are on the underside as shown.
Here's what the interior of a drum head looks like:

Note the white block in the bottom left, and in the center. Those are the spots where the drum pad actually connects to the the components shown. It looks like the pad has a piezo that's connected to some wires which go into that connector, probably so that the pads can be replaced easily. Here's what the other side of a pad looks like:

You can see the piezo in the center, plus some foam padding. The four rubber plugs are how the pad connects to the main drum kit. I've got a few extra drum heads if anyone needs to fix one. (One of each color, should be working fine, unlike the rest of the kit!)
And now for the payoff: the main control board, a closeup.

Note the inelegantly soldered wires to various spots on the main board. Those are the points that correspond to each drum. Two of the wires have come loose and aren't connected in this picture.
Finally, here's a neat bit of circuitry:

The board on the left is a MIDI decoder (with the MIDI port not attached), hooked up to a barrier strip that leads into a wire bundle. This wire bundle connects to the Rock Band board shown above, and the whole point is to let MIDI signals control the Rock Band drum board and send signals to the XBox, thus letting one play Rock Band Drums, using any MIDI device.
The whole setup's been tested a few times and works great, but isn't in a very usable condition - a lot of stuff has to be moved around, and it's a bit clunky. Plus, I need to resolder those wires.
More on this subject later, including pictures of the MIDI device that's the point of the whole thing, the building of the enclosure to hold all the circuit boards, and maybe even a video.