A/C auto off
 

I have read that the new Insight will turn off the A/C when stopped if possible, probably because the A/C is less efficient without forced cooling.

Perhaps a simple circuit can add this to any car by sensing the speed and opening the circuit to the A/C contactor below a certain speed (except for the first few minutes of power on).

RPM switch would be sufficient. I doubt very many people frequently drive below 1200 rpm so setting a switch(ghetto of running a wire along the guide and another exposed copper band along the edge) would do this. You can probably buy something more expensive or a voltage dependent switch running in directly connected to the alt would do it(low voltage at low speed higher voltage, but you have to put it in before the inverter and before any diodes that limit voltage).