I support Natural Gas as the best alternative fuel that can be used today. Not only does it burn more cleanly than the other fossil fuels (coal and oil), but there's also plenty of it right here in America, which would allow us to not be so dependent on foreign oil. Also, the technology to use this fuel (at such a massive scale) already exists today, unlike other alternative energy like wind, solar, or "clean coal". (I don't believe in clean coal at all.)