Funny. I flatted this morning too. Tried a new route to work today, and as I was riding in the dirty bike lane, something on my bike went 'Thunk' and then something was striking my fender with every revolution of the wheel. So, I pulled over and checked to see what I broke. Turns out I had a sheet metal screw or something sticking out of my tire. Never got a flat THAT way before. So, I replaced the inner tube, pumped 'er up and away I went. When I have got some time, I'll patch the punctured tube and use it next time I need to switch an inner tube out.

I definitely think having spare inner tubes is the way to go. I don't know about you guys, but I find it difficult tracking down small puncture holes out on the street (especially since I didn't make note of where I pulled the screw from). It's easier, IMHO, to inflate the tube, stick it under water in the sink, and see where the bubbles are coming from. And having a spare inner tube is faster than isolating the hole, roughing it up, gluing it, waiting for the glue to dry, and patching it.