I myself carry two CO2s ( I havent quite got the hang of it) and a pump. Plus a adapter for the CO2. The pump is in case I screw it up.
I stop for anyone who looks in need( when not commuting), although I am useless, Ive got some extra stuff and people fixing tires often like a chat while they struggle getting tires on rims and stuff. Sometimes its cute guys and we chat gear, and things, while they fix whatever and I get a good perve on their legs!