Great ideas that never saw the light of day

Unfortunately, the whole premise never happened, but it was a hell of a good idea:

eGlaz

The notion was to create and sell the notion of self-darkening window glass, to be used in the home, industrial, and automotive markets. (The physics is very available, but people still have to be convinced they want to do it.)
Rico spent quite some time with his friend Carl Allen developing it, but we never got it off the ground. Too bad. We could both use the royalties.