I thought it would be nice to take a shower on the trail from time to time. I came up with a shower that uses my 2+ liter platypus bags. To take a quick 1 min shower I would use no soap and one 2.5 liter bag. For a shower with soap I would use two bags in sucession, one for soaping up and one for rinsing. If Im in camp for awhile and its sunny I put the bags on a dark object and let the sun heat them. Otherwise I bring along a little extra alcohol and heat about .5 liter water on my stove for each bag.
The shower attachment and cord to hang the bag weighs around 1 oz. Since I use aqua mira drops I can use the bags for storing/carrying drinking water as well.