Over the summer I ran the Aneto Marathon and as I mentioned earlier there was a list of required gear. Some races give you a shirt for finishing and others a belt buckle, for this race they gave everyone a TrangoWorld running pack ($60 value), very nice, and a *small mesh bag. It was required to bring some sort of pack, but you had to bring the mesh bag.
This was the first time I have ever heard of anything like this for a race or sold in a store for that matter; I have since looked and REI doesn’t even sell anything that would even work. The course seemed to be more conscious of environmental impacts than any other race I have been in. It is basically a small velcro mesh lobster trap for your running garbage. It works great for empty gel packs and is the one thing I take on just about every run. It also made me more trash conscious, not that I would ever throw it on the ground, but I see gel wrappers everywhere. I know runners wouldn’t do this, I want to blame the cyclists. I try to pick up as many as I can.
If you see anything like this in the stores, send me a link.