Sometimes simple ideas are the best, and IT Clips has a good one. Millions of bicycle inner tubes end up in the landfill each year. In an effort to give them a second life, the company was born. IT Clips are plastic threadable locking buckles designed to accommodate a retired road or mountain bike inner tube. The buckles clip together so you can use the tube as an adjustable loop, and they come with hooks that thread around the clips turning the whole thing into a true bungie/tie down. So far they seem strong: I used mine to strap down as much lumber as would fit on the roof of my Subaru, and hung bikes with them from the rafters in my garage for storage.
It's super easy to attach the plastic clips. Just cut your tube on either side of the valve and thread it through. It took me a couple of tries to get the hooks on--I kind of felt like I was playing one of those bar games where you have to get one piece of metal off a larger jangle of twisty pieces--I couldn't get it to work, and then suddenly the clip was on. They run $4-$4.50 for a set, enough to make one recycled bungie cord. To find a retailer, click here. For IT Clips action photos click here.