For just pedaling around town, I carry a micro-inflator, three CO2 cartridges, two tire levers, a spare (usually new) tube in a plastic baggie, a patch kit, and a Park MTB-3 multi-tool. For the long training or touring rides, I add a frame pump in one of the jersey pockets. So far, so good, the only time I've had a long walk in the past three or four years was when the LBS took my wedge pack off the seatpost for a service job, forgot to put it back on, and I forgot to check it until I had a flat on the next ride way out at the turnaround point ;-)