Some of my worst nightmares have been troubleshooting weird switching circuits. Sometimes the conclusion was that the wiring was never right to begin with...there were not enough wires to do what had to be done, but no one ever really noticed until now that "With this switch down you can't make the other 2 switches that go to the hall lights work."

I appreciate knowing all these ways of doing it, but still maintain that wiring 3 and 4 way switches is not the time to show how creative you are.