A trick I learned from a friend, who complained that his key ring was always wearing out his pockets (and causing coins & things to trickle out) -- if you have a key fob (or in my case, An ARC Infinity AAA light) attached to a short (3-4") lanyard, you can hang it so it rides just outside the pocket, and the keyring is suspended inside the pocket.
Benefits: -no pocket wear at the bottom
-easier to fish your keys out, no reaching all the
way into a crowded pocket
-the LED light is instantly available
-it's easier to find coins, etc. at the bottom of the
pocket without having to remove the keychain
to find a quarter, etc
Disadvantage: people are telling you that something is hanging out of your pocket! (At least until they get used to it). No problem under a sportcoat or jacket, since it's hidden.

I've tried this technique against normal pocket carry, and for some strange reason a bulky keychain doesn't tend to pull your pants down as much -- maybe because the weight is supported by the short stretch of outer cloth between the pocket and belt.