Mavic is making a shoe/pedal combination that uses a magnet to connect the two. I wrote a long review of them, that got lost in cyberspace when I tried to post it. The short version is they work pretty good.
I have seen reviews about them on Bicycle’s and have been thinking it may work on one of my Uni’s.
So thanks I’ll have to test for myself.
Here a photo of the Pedal and the shoe fit’s onto the pedal. 
