Hippo Water Roller

http://hipporoller.org/

http://en.wikipedia.org/wiki/Hippo_water_roller

http://www.fastcompany.com/1309505/balancing-tradeoffs-evolution-hippo-roller

http://www.treehugger.com/sustainable-product-design/project-h-delivering-water-in-africa-with-hippo-rollers.html