Helio Pressure Shower
I read about the Helio Pressure Shower in a review on Expedition Portal and thought I'd give it a go.
Short-term, I love this product. It compacts, it's construction is stout and it provides good pressure. By mid-afternoon with full sunshine exposure it's ready to deliver a good, warm shower. At capacity, 11 liters, there's plenty of H2O for two showers and it's still portable.
The Helio uses air generated from an integrated foot pump to pressurize the water chamber, creating nice pressure through a seven-foot tube to a standard kitchen sink sprayer. The unit collapses neatly, but with a bit of persuasion, into a ventilated carry case the size of a medium mess kit (seen in lime green in the top image).
Given the physics of its design, the fill port it located at the top of the bullet shape tank, just underneath its reinforced carry strap. My only gripe with the product is this makes it a bit of a trick to fill, especially with hot water, trying to negotiate the strap away from from blocking the opening. Perhaps a quick release clasp here would do the trick.
For under $100 it can't be beat.