Lint.

In all seriousness, I usually have my cell phone (Droid2 Global), a pen (Surefire sometimes, but more often just a Pilot G7 retractable), and my Leatherman Skeletool CX. If the Skeletool won't work with the pants I have on, I'll take a smaller folding knife. I don't like a whole lot of bulk in my pockets.

Wallet in the back pocket.