If you own a pinball machine you should own a roll of this:
http://www.amazon.com/gp/product/B000QDRRNE/ref=oh_aui_detailpage_o06_s00
I use this not only on my pins but I end up using it around the house too. It's only $13 @ 75 feet long and I am on my third roll so far. I use strips down the sides of my PF's and backboard's to prevent it from scratching the side of the cabinet. I use it on the inside of BB hinges so it doesn't scratch the side rails. I use it down the edges and back of my glass to prevent rattling. Those are just some of the examples where it has come in very handy.
Jesse