(edit: The film of the electric retracts has been superceded - I will get a link to it and put it here soon) The electric retract I was praising to the heavens a day or so ago. is a superb electronic design by Pat Gardner and Peter Finley, which complements Ben's very elegant mechanical system. When retracted, the control panel shows a red light (as in "Stop, don't try to land" - like a red flare from the ground), but when the wheels are down you get a green light. All very logical, and logical though the manual version was, with colour coded toggles, I think that most people will be a lot happier with this system.
In case anyone is worried, in the event of an engine failure with wheels up, the retract has a back-up battery with power sufficient to get the wheels down.