Here is one possibility if you are interested:

http://www.motherearthnews.com/Moder...Old-Tires.aspx


For those who live in Indiana:
http://www.manta.com/mb_44_B1216_15/..._shops/indiana

Georgia:
http://www.manta.com/mb_44_B1216_11/..._shops/georgia

Maine:
http://www.manta.com/mb_44_B1216_20/...ir_shops/maine

Colorado:
http://www.manta.com/mb_44_B1216_06/...shops/colorado


This might e worth it if you don't destroy the tires for the rims.