Has anyone built a four wheel PPV out of two bikes? With a bench seat and two sets of pedals, maybe a basket on back.

I have always wanted to take a couple of bikes and use the wheels from these. Build a tube frame like a Go-cart that sat down between the wheels. Which would give you a good balance. Make a bench seat with two sets of pedals so one person didn't get ALL the excercise. Maybe put a basket on the back so you could bring home the groceries. With gasoline prices going up again, this could come in handy around town. I was wondering if anyone here had made something like it.

Check out  www.atomiczombie.com they have proven plans using donor bikes for most if not all the parts required.