Like the others I carry CO2 as my primary on the road inflation, but I just bought a new pump though, because the little emergency backup one I had failed me miserably.

The new one is very small too - its a Topeak Micro Rocket. Supposedly you can get up to 160lbs of pressure out of it, but I sure wouldn't want to have to try.... I did want to be sure that it was possible to at least get the tire pumped up enough to ride on though, so I did ask to test it out before I bought it. It was REI, and they are generally pretty accommodating. They let me take it out and give it a go. I was pretty impressed. For how tiny it is (fits in my seat bag) and how much it feels like a slightly long lipstick, I was able to get a decent tire pressure pretty quick. I was looking at the Leyzene pumps too, but this one is just a titch smaller.