This week is for all the REAL geeks in da house! I'm talking schematics yall. OK, this is the point where most if not all readers of this will leave the page in search of something more interesting. I take no offense as the subject matter can be a little dry for the average pallet. If you have an acquired taste for this kind of stuff then read on...
Discovercircuits.com has every conceivable circuit/schematic one could desire from AC to DC power supplies to zero cross detectors.
Bust out those soldering irons and make something useful, or not.