Show us your Titanium! - Ti and Stainless bikes

They really are interesting bits of kit and available in a whole range of options including multiple chainring variants.

http://www.schlumpf.ch/hp/schlumpf/antriebe_engl.htm

The unicycle ones are a real hoot:

This means: a 20" wheel works like a 30" in high gear mode, or a 24" is like a 36" coker. Try a 29"er! It runs like a 44" wheel!