For the do-it-yourself crowd, there is a series of videos over at YouTube by a group called Green Power Science that you’ll be interested in seeing. The one below is a good example of the quality of their videos. It details the construction of a trough mirrored solar water heater that can be made easily and cheaply with few materials and very few tools.
After looking at this one, go over to YouTube and browse the Green Power Science collection. It’s time very well spent.