A good way to reduce your water usage is to take a 1-gallon milk jug, poke a small hole in it near the bottom. Now plug that hole with a golf tee. To avoid losing the golf tee, attach it to a string tied to the jug's handle.
This is a great camp gadget, especially with Boy Scouts, since children are usually especially wasteful of water. I know a guy who says he can take a shower with 1/2 a gallon from one of these things.