Here are some fun "plays" with rainwater harvesting systems.
Ferrocement urn cistern designed and constructed by Art Ludwig of OasisDesign.net
Show the Flow. Water flows down steel downspout to raingarden. Steelhead trout swim up to the roof source. Insurance office, Portland, Oregon. From Rainwater Harvesting for Drylands and Beyond, Volume 2.
Seattle Drink Cistern (photographer unknown)