Hey there. My uncle grew up with this guy, Andy Gregg. They were both avid cyclists, and many years ago Andy began making furniture out of bikes. I'm not sure if this counts as alt bike, but it's definitely cool.
Take a look at some of his work:
The chair in this picture belongs to my uncle, it's in his shop. Made out of two bikes that he totaled way back in the day:
And some more:
Oh, and if you look at the "Exhibited" tab of the website, you read for a bit and then come across that Lance Armstrong has some of the chairs at Mellow Johnny's.