Ok I like Mitch's idea. Allthough it is impractical as of right now and will probably stay that away unless sumone gets cracking. It still is a funny idea.
Also Hydrogen is hard to store in it's elemental, diatomic state because of it's density. From some things I read is you would have to basically build a fual tank with nanotechnology and make it have pretty much no holes. It'd really suck if you drove home and had a 1/4 of a tank of H2 left. Then the next morning you had almost none left. Sure it wouldn't escape that fast probably but still. What has also been stated is you need alot of H2. Fusion power would be the only clean way to produce all of it. That too even uses Hydrogen. Good news is the hydrogen vapor wouldn't accumulate in vast amounts to become flamable in a Hindenburg way.
Unless some people get cracking and solve some technical issues. SUGAR power is the next fuel source.