While searching for ideas on the net (also see post "off my rocker") I had come across a neat contraption someone had made. They built a box with a water tank inside, and a "clean water" tank on top. They placed a single solar panel on the ground, leaning agianst this box that was higher than the panel. He had a water line coming up from the ground, feeding into the system. The water fed through copper pipes inside the solar panel, circulating the water as it heated up. I may have the set up described wrong but it sure looked interesting in the picture.

He used this for warm water to wash up with, and he made it himself. Can't for the life of me find the site now, but i did print it out at one point and will look for it.

I found that website I mentioned. This probably isn't quite what you were looking for but perhaps it may help with ideas? This uses thermal to heat the water.

http://www.ata.org.au/articles/63shw.htm

bp