Ok, here's a recycling project done wild.

I have some plastic Birkenstocks -- I've had them for years -- that have worn down from use. A few years ago they even had holes in them that I filled with Shoe Goo and I coated them with aerosol rubber.

Well, the soles had really worn away and so the shoes had cushion to them, so I made soles out of old exercise floor mats that I glued on with Gorilla Glue, and then painted the sides. Believe it or not, it seems to have worked.

The exercise mats are a bit slippery though, at least on inside floors. Any ideas for a better sole? I have another pair that maybe I will try to rehab.