I bought the the Blackburn Mini Frame pump in March of 2002. Thus far its rolled with me for about 6000 miles and I count on it 100%. With the numerous flats I have had, it has always baled me out and got me rolling again in no time.
Its simple design makes it easy to use, convenient to stow, and utterly reliable. Its a universal pump in that it's convertible between presta and shrader. I have always used it for presta but I know that if I am riding with someone who has shrader, I've got them covered. The rubber gasket inside the head is durable and thus far has not needed replacement. Even exposed to the elements the hardened plastic barrel barely shows any wear. The overall contruction is very solid, it actually fell out of my pack once at about 25 MPH and bounced on the asphalt. It received a few minor scratches but still continues to work beautifully. An additional design feature is the flip out handle. The handle snaps out to form a t-shape, this allows the user to get a good grip and really bear down on it when the pressure gets high.
My pump has been used for both my MTB and my roadie, working equally as well for both. The only issue would be that getting past 75-80PSI on a road tire might take a little brute strength. Of course, 75-80 PSI will get you home or to the nearest bike shop.