Ruger P95, spare hi-cap, trusty MagLite, and a Leatherman Micra on my keychain. Recently I've also been carrying the Columbia River M16-13 folder I picked up at a bargain price. My wife carries our cell phone plus a Kel-Tec P32 and another Maglite.
I won't carry OC, because if I ever have to use the Ruger I don't want some lawyer claiming that I had a nonlethal option and chose instead to kill because I'm one of those gun nuts. I can argue that the knife was not an option because it's too dangerous to close to contact distance.