I recently picked up a few of these to see if they were useful or just another gadget. Being able to secure excess web strap lengths without having to cut or tape them is handy. I put a couple on the kids' backpack shoulder straps prior to a long distance plane/car/walking trip, and they held the strap excess securely for two weeks. I had the same good results with one on a 3-day pack shoulder strap, and on another pack with some cinching straps--the straps stayed secured and out of the way. Unfortunately, I noticed too late that Supply Captain has a very good price on them right now; I paid too much, but am still happy with their performance. I've only found keepers sized for 1" webbing, but maybe you'll have more luck if you need something bigger.
http://www.rangerjoes.com/web-dominator-pi-3966.html