My stance has always been:

1. I must carry a pump in case I have multiple flats,
2. So if I'm carrying a pump anyway, why carry a CO2 inflator?

But I'm starting to think this:

1. I could a CO2 inflator, and also a super-small pump that is slow and hard to use, but use it only if I have multiple flats.

The two advantages of this new world view are (1) faster flat repair for most flats and (2) the pump and inflator stuff all fits in the seat pack, so the frame is neater.

I'm thinking of these:

http://www.amazon.com/Portland-Desig...9O9KTIAC&psc=1

http://www.amazon.com/Topeak-Micro-R...I1SDZKUMSODL5R