If you are looking for a nice DIY Binary Clock design have a look at this one by Kenneth Finnegan. It uses a sweet DS3232 RTC, but at a cost of $7.63 it better also do the dishes…

“The time is kept by a DS3232, which is a very cool chip in that it has a built in temperature sensor, which it uses to compensate the crystal to try and keep better time, and the crystal itself is built into the package, which is an advantage since I’m using this on a breadboard, and crystals don’t seem to like the stray capacitance on the boards that much.  This chip is quite a bit more expensive than the DS1307 I’ve usually been using for these projects, but both use the same address over I²C, so replacing one with the other is simply a matter of connecting the correct pins.”