http://www.thefuturepeople.us/ 

"The Future Cycles project was born from the realization that the American transportation infrastructure will far outlive the gasoline-powered vehicles that we currently use on it. Our question is, “What transportation alternatives could replace these vehicles that would deal with shifting energy availability and still provide the kind of independent travel that our infrastructure requires?”

Some interesting rides these folks are putting forth, not sure how realistic these are but neat to see the thought being explored.