We went to a Xeriscape Symposium on Saturday and the best topic was rainwater harvesting. The only trouble is you actually need some rain to harvest!
Texas A&M has some information about calculating the size of the storage tank for the size of your catchment area and flushing out the first dirty part of the water, filtering, etc.
It would have been nice to get more ideas about landscaping with plants that do well in the dry times.
Steve won a door prize: a soaker hose. And I won a small book about local gardens.