For fear of looking stupid, I don’t dare use a pun such as ‘got some time on your hands to read this clock’, and I’ll get straight to the point. The math clock makes you solve the problem at ‘hand’ (quite literally) to determine the time. By day 2 you should be ready for advanced calculus.
Available at Thinkgeek for $27
Grew up back East, got sick of the cold and headed West. Since I was small I have been pushing buttons - both electronic and human. With an insatiable need for tech I thought "why not start a blog focusing on technology, and use my dislikes and likes to post on gadgets."