Found via Cyclelicio.us on Instructables.  Here’s what the guy behind this says about it:
“I’ve wanted to build a custom bicycle for many years. I started wondering how fat of a tire I could accommodate on a bicycle. I had seen pictures of the Hanebrink Technologies extreme terrain bicycle, but wanted something still more extreme. The problem I considered was one of drive train alignment. With the fat tire, the chain had to shift too far outside of the normal bottom bracket to rear wheel alignment, in order to clear the tire width. I also wanted to make this work with gears, as I new the large tire would weigh a lot. Originally I wanted to spoke up a fat tire rim with a standard bicycle hub, but this proved impossible due the the small rim size with the large tire.”
Well done, sir, well done.  Another pic after the break…
The best part is, there’s full plans online for you to make your very own!
