Neat thread! I use a heavy duty biner thingy made for boating. Holds two sets of keys and a Leatherman Micra on my belt. I've tried clips, but just don't trust them - its gotta stay on my belt.

An off topic reminder - BEWARE of heavy sets of keys -- they can cause expensive damage to ignition switches on steering columns. It can sometimes take years but WILL cause it. Know a guy who did it twice and finally learned his lesson, one costing $700-$800.