Popular Mechanics has a slideshow of 18 oddities in bathroom design. Pictured above is a floating bathroom that the US National Park Service installed in Lake Powell (UT/AZ) to persuade people there not to simply relieve themselves in the water. The official website confirms that there are, in fact, six such floating facilities.
Link via Digg | Photo by Flickr user Niels van Eck used under Creative Commons license
Well, the floating latrines on Lake Powell do happen to have restroom facilities, but their main purpose is to serve as dump stations for port-a-potties. You can imagine how quickly one of those little numbers can fill up with a medium to large quantity of people out camping on the lake, so these facilities are fully stocked with a dump and non-potable water for rinsing afterward. Quite handy and I've utilized them for this purpose a number of times myself.
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