I recently broke a string (making my new record of two minutes before our festival performance). Since i didn't happen to have been carrying around spare string, I had a bit of a problem.
I'm just curious about what other people use to replace a broken string, wheter it's a special kind, or if you just get it from your local music store.

I just keep a stock of yellow braided nylon string that I got from a brass repairman. I've heard of other people using braided nylon fishing line, but make sure it is BRAIDED (it keeps it from slipping). Also, don't re-string too tight, it can damage the valves. I remember some one once told me they used unwaxed dental floss in a pinch, but I don't remember how that worked out for them.