The Clucker sent me this photo today - it shows how you can get home after a nasty puncture by using a $5 note as a sleeve within the tyre. I've read about this in my bike maintenance manual, but never seen it in action.
The manual I have was written by a yank, so he was writing about paper currency. I imagine out plastic notes are even better for this sort of thing, being much tougher.
I always carry a bit of cash with me when going for a ride - partly in case I need some food or drink, partly in case I need to catch a taxi home (!) and partly for this sort of thing. I've never had a split this bad, but then I'm not riding around on expensive, fancy, lightweight racing tyres.