I designed a lock for medium security applications. (I'll try to get some pictures up when I have my pc back.) It uses a bit of the design from another type of very high security lock, of which I forget the name.
The basic premis is that you have a larger than normal cylinder. cut into it is a a key slot that is twice as wide as a nromal key slot, but since it is horizontal it's twice as tall I guess. Anyways, there are 2 sets of 4 (or 6) pins set at an angle. The key is flat with 2 parallel lines of holes, at different depths, to drop the pins to the correct height. That's prettymuch it, but it would seem to me to be very hard to pick. Any thoughts on this?