No joke. As outlined in Waste & Recycling News June 21, 2010.
Liberty Tire Recycling of Pittsburgh in partnership with Performance Bicycle will pay you $5 per used inner tube brought to participating locations(not defined in article). Says to visit performancebicycle.com to get the locations.
I have enough old tubes in my garage to possibly retire with the $5 per.
There was no way to link the article. It came to me via snail mail. Don't know if it is credit or real cash you get but I assume Performance sees it as a way to both build traffic and be "green". The article did say that the tubes would be recycled into the same stuff car tires are used for, playground mulch and asphalt additive to name a few.
Most of us have been recycling tubes for years anyway in a multitude of ways. Just thought some might like to know about this.