While prepping for an all day road trip to Bend, I was stewing about how to fasten my bikes snugly to each other (outside of bungie cord or small rope) on my hitch rack. I ran across these Velcro loop straps at the local hardware/clothing store. They come in a multipack, cheap, very effective. Didn't loosen. Stayed snug, easy and quick to undo. Makes a nice parking brake as well. They can be attached to each other to make a longer strap. Probably some other uses will pop up: tourniquet, emergency pump strap, solidarity bracelet, handcuffs.....
http://www.flickr.com/photos/61726328@N03/7904276468/