I'm always on the lookout for new ways to geekify my home. Here are three versions of math clocks. The first one, I actually already at one point owned...I'd made my own version back in college, but it got broken during one of my many moves.
Both the clock above (the radian clock) and the clock below (the pi clock) can be found here for $14.00 each.
This clock, my favorite one, was available here, but it sold out on Thursday this past week.