We carry spare tube, patchkit stuff + Topeak Mt. Blaster pump on the bike.
This pump converts to a mini floor pump with foot peg, T-handle, hose . . . and 100 strokes gets in 100 lbs of air into a 700x25 tire.
Also choice of tires can avoid flats. We use Maxxis Re-Fuse 700x25 folding tires and in 5,600 milkes of pedaling in 2011 (tandem and single bike) had ONE puncture.
Some tires wore out and had NO punctures.
Just our experience/input.
Rudy and Kay/zonatandem