If you have a moment, check out this site Suntory ~ Mermaid II about a boat that uses Wave Propulsion to sail the seas. While you're there, check out Horie's diary. Horie is sailing this boat from Hawaii to Japan. He has an online diary that provides his daily progress. I've been checking on him since his journey began back in March. Have to give this guy credit for sticking it out this long!
I think the boat's design is unique, and with the high cost of fuel these days, I'm hoping they are able to make this work!