yep, I'm similar to most of you guys. I had a couple of incidents where I thought I patched the hole only to have the tire still go flat shortly thereafter. once was on a bike my gf was riding and she didn't even notice til we stopped for a break, I can't believe she didn't pinch flat. generally i wait till i have 4 or 5 that need to be patched then I patch them all at once, inflate them and let them sit awhile to make sure they are okay. Like beanz, I prefer to know for certain that the tube is going to work so if I do simply patch and put it back into the same bike I make sure that my next ride on said bike is close to home like in Central Park where I can bang out a few laps to get my mileage in and only be a 20 minute walk from home worst case scenario.

on my bike i carry 1 tube in a small seat bag with tire levers, patch kit, and a multi tool. I ride on gatorskins and so far haven't had a flat with them. I went through a stretch where I got a lot of flats while testin out some cheaper so called kevlar belted tires. at the end of the day, the $65 for the gatorskins is worth it. I bought a $15 nashbar tire but spent another 35 on tubes from either flatting or having the bead slip and the tube explode! Not to mention the time wasted repairing the flats