The Chrome Calculator Belt Buckle ($10) is almost exactly what it sounds like. The only thing they failed to mention is that it also serves as an incredibly effective chastity device. You can put it on either way (numbers up or down), so that you can use it, or someone else can do the number punching for you. It's pretty f'ing dorky, but I got one anyways. I like to keep a real close eye on my secretary when she's calculating expense reports.
The Amazing Chrome Calculator Belt Buckle [slashgear]