Because apparently there's a market for exhilarating ways to kill yourself (move over, dangerous carnival rides!), a doctor (OF DEATH -- move over Kevorkian!) invented the StreetFlyer, a bike ridden while suspended face-down (like this one, but way more modern). NICE BUTTCRACK, LADY!
Created by Dr. Carsten Mehring, the StreetFlyer lets a harnessed rider transition between walking along with the 'bike' and a prone, lying-on-your-stomach position where you pedal the single rear wheel with your feet and steer the front pair with your arms.
At the moment the StreetFlyer only exists as prototypes, but apparently a more marketable and 'practical' version is being designed that you could end up seeing on the streets some day.
Oh man, can you imagine finding out somebody cut your breaks after you're already racing down a hill on that thing? WTF are you gonna do then?! SPOILER: Die. Probably hanging out of a parked car.
UPDATE: Short video added after the jump thanks to Allie, who was really hoping to see some crash-test footage. Ditto.
Thanks to Sam, who rides bikes the way God intended: with no seat. Mmmm, makes a butt feel gooooooood.