Another vote for the road morph g. Funny thing is, in two years of commuting, I have only used it in an "emergency" once - to help a stranded road cyclist.

I carry co2 with my road bike along with a much smaller pump. The co2 I have used twice - once with a situation similar to the op. I had a puncture but unknowingly produced a pinch flat when reinstalling the tube and blew through two cartridges before I figured out what I did.

Here's mine: