If you have hundreds of feet of garden hose like we do, you know that the water gets very warm in the hose, and can run warm or even hot for 5-10 minutes. So why not take advantage of this free hot water?
I did just that by constructing a frame from four 34" scrap 2×2′s, screwed together at the corners. Then, I drilled 3/8" vertical holes in each corner and run cord or clothes line through, tying at the top and knotting at the bottom to the correct lengths. The cord is then attached at the top to a hose clamp secured on a hose. The hose is then connected to valve and then a shower head I picked up for about $2. You then drape the hose over a tree branch. For privacy you can attach a tarp on the inside of the shower as shown.
For a more functional DIY solar shower that I built for about $25, check out my 20 Gallon Solar Shower Plans for a shower that works even in cooler (sunny) weather and retains its heat after the sun goes down.