No flats on my commuting bike(s) for two years. Now on a run of four in three weeks.
EDIT: Now 5! Realised that the tyres are full of tiny (2-3mm) chunks of glass, and the tyre tread is sufficiently worn that the small chunks are getting worked through the inside of the carcass. Ordered up some Continental puncture resistant tyres - hopefully that will put an end to it.