Behold the Slingshot Farmboy 29er frame. This is a 2007 model that is on the cutting edge (at the time) of the 29er craze. I like to see this kind of forward thinking, even if it's so wacky looking:
How much do you trust this cable?
Quite the steer tube
The frame design is centered around a flexible piece of fibre where the top tube meets the seat tube, and then a cable and spring for the down tube. The frame flexes in the middle, rather than at either end such as a conventional suspension system. Pretty rad.