Tom Van Baak has a fascinating obsession with timekeeping. His website, www.leapsecond.com, has a great deal of information regarding timekeeping and his vast collection of odd and accurate timekeeping devices. He even wrote a nice paper which details the state of the art in amateur timekeeping. The short of it: amateurs can achieve ridiculous accuracy for fairly cheap amounts of money.

Oh, and he took some photos of the Venus transit too.