I searched Google for: plastic key clip

I had many hits, to include plastic key clip and pictured was a plastic clip we are all familiar with.

I also found plastic bolt snap at this site: http://www.umei.com/buckles-plastic/plastic-bolt-snaps-hp313.htm

And lastly, I found a site that has a use for them:

http://www.mhcable.com/~yocraft/misc/yosling.htm

Not sure I like "bungie" or "bungee", however it does work with BOTY!

Jim