Follow the link bellow to find one of the best uses of steam since R. Trevithick thought about putting one of his engines on wheels, and the rest became history.

http://www.newscientist.com/article.ns?id=dn3321

If I had a suspisious and paranoid frame of mind I'd be tempted to think that the reason I have not seen any steam powered speed boats (other than a few pictures of Turbinia gate crash a fleet review) is that the petrolium industry buried it and probably at midnight in an un-marked grave.