That steam powered plane is cool. Trouble is, it's not exactly alternative fuel. They used oil.
I guess you could power one with wvo which would make it alternative. A simpler, cheaper, possibly more efficient method of wvo propolsion is diesel. Anybody got any biodiesel powered bikes out there?
There is a company that makes a diesel motorcycle for the military. It is klr 650 based and is supposed to be good for 120 mpg. There is supposed to be a civilian one in the works, but, it will be $$$$$.