I just recently heard of the Iranian Push Up from a Steve Maxwell podcast. I think some people call it a half moon push up. I also just discovered a simple tool called a push up board. Not really sure it's necessary, but I haven't ever tried the push up board to see if it offers any advantages.
I'm going to play around with these and see how I like them for the next month or so. New movements are always fun to try to learn and get better at.
Here is a circuit being done with a push up board.