I wrote a fretboard chord/scale utility for the Amiga years and years ago. It was awesome. One of the things it did was, if you clicked notes on the fretboard, it would tell you every possible chord those notes were part of, as well as every possible chord that could be created from one or more those notes. It would totally win this thread. All I need is to install an Amiga emulator and sort through tons of junk to find the CD it was burned on.
Meh.