My son has one of those multi-pin impression toys where you press your hand on one side and the pins move and you see your hand impression on the pins on the other side. He loves it. I've seen some large ones at Childrens Museums but it seems like there needs to be an instructable on how to make your own, preferably a giant one.
I've found some steel sheets online that would make good holders but couldn't come up with possible items for the 'pins'. What are your ideas?