I must have a similar mindset to Numbnuts. As I use panniers on my hybrid I have plenty of room. I have enough tools to almost strip the bike at the roadside. During a recent rationalisation of what's in my pannier I decided that the new chain was a little overkill and removed it but I left the brake and gear cables in there. I carry a rear of each. If a front cable goes I can fit a long one then coil up the extra just to get home. Three tubes and two puncture outfits, so I have left one out. I have a couple of triangular bandages. As dressing they are all that's needed. I have a waterproof jacket, and depending on the weather I may well carry a softshell jacket. Also some lightweight trousers. Then I carry a wallet, cash pouch and mobile phone. No need for a camera as the phone has one. Last but not least I always have my bus pass. if anything disastrous happens I can bung the bike in the hedge and catch a bus home. One advantage of riding a cheap bike.
In the last three years of regular riding I have only had a few punctures and haven't had to use any of my other tools. It is tempting to leave them out but just in case.................
