Maths rock! Okay maybe a slight exaggeration on my part but I am loving the Jumbo LED Binary Clock. Available on Think Geek for $49.99 after discount, the geeks will heart this clock. You can install it on the wall or on your favorite flat surface, select BCD or pure binary mode, set the time, and you are good to go.
BCD or “True” binary display options, selectable by switch
12 hour and 24 hour display, selectable by switch
3 brightness levels
Wall mountable, or can be used tabletop with included brackets
Battery backup of time during power loss (uses 3 ‘AA’ batteries, not included)
Available in your choice of crystalline blue or bright red LEDs