I carry a Park glueless patch kit and a couple of alcohol swabs (to clean the tube), a spare tube, a pump or CO2 inflator (depending on which bike I'm riding), and a Crank Bros. Speed Lever. If you get a cut in your sidewall, you can boot it with a dollar bill. I also carry a multi-tool with a chain breaker and a missing link. With this set up I've never had to walk home.
Check out the
Crank Bros. website for the Speed Lever.