Thanks for the recommendations, fellows!
I've had really stellar luck with Crank Brothers' original PowerPump (black, free as a prime for buying something else). It is light, compact, and the hi-volume/high-pressure switch really does work. I managed to hammer 7bar into a narrow tire with it once (once!...after which my arms fell off) and it works great on touring tires. Yes, it takes about a million strokes, but they're short and easy, and it seals airtight on either Schraeder or Presta valves. It fits nicely inside my Ortlieb medium underseat bag, and provides an emergency backup. See: http://www.crankbrothers.com/pumps_powerpump.php
Back in 1991, I was touring Oregon's Diamond Peak Wilderness Area when Dad got a flat at 1890meters on Emigrant Pass. I repaired the flat and pumped his tire for him (it was the week before his 74th birthday), stood up to congratulate myself on a job well done and...stepped back across my Silca Impero frame-fit pump, breaking it in two. Of course, I had a flat later that trip, and if he hadn't also had a pump I'd have been out of luck. Lungs alone won't do the job.
Ever after, I've carried a spare pump for all my solo tours in case something happens to the main frame-fit one. It isn't ideal, but far better than stuffing the tire casing full of fresh sagebrush every kilometer or two and going lumpty-lump as I slowly kill the rim.
Something like the Topeak Peak DX would be an ideal "second pump" in the back-of-beyond, too.
"Belt and Suspenders!" Dan.