I had my first flat in a long time last week. I was on the return leg of my commute when my front tire blew. I was lucky...two minutes earlier I was going pretty fast down a hill. The inner-tube had a hole at the base of the presta valve. I think I might have tightened the nut too much and stretched the rubber. I carry a spare tube and tools so I was good to go (just a little out of practice, plus the first time I used a frame pump). The great thing was that 4 cars stopped to ask if I needed anything.