Japanese toilet maker Toto has invented the world's first Toilet Bike, which converts human poop "harvested directly from the driver" into biogas, Treehugger reports.* The seat is a toilet, so if you ride it with your pants down, you could theoretically defecate while you ride, thereby fueling it.
But that's not all! Toilet Bike can also "play music," "harness residual light imagery to write messages in the air as it passes by," and talk, "which is an existing function on Toto products." It is currently on a 600-mile cross-country tour of Japan, and will visit Kobe, Kyoto, Tokyo, and this "ass-shaped boulder," for Toto's "Green Challenge" campaign. [Treehugger, TotoTalk]
* Update: Reports conflict! Though Treehugger reports that Toilet Bike is poop-powered, this Japanese source says that, though powered by biogas, a human cannot drive and poop simultaneously while on this bike. Or, like, if they did, it might not work out that well. Thanks, Kyomara