If your concerned about not freaking out the sheeple, or if you need some protection for your piece (ie: if you're rock scrambling or whatnot) check out the Safepacker by Wilderness. Dillon carries 'em for most common pistolas, and Wilderness will make you a custom as well.
http://dillonprecision.com/template/p.cfm?maj=8&min=0&dyn=1&
As I heard it, the guy that started Wilderness was into SAR and wanted to be armed without drawing a lot of attention to the fact. These things are quite low key, provide very fast access, have absolutely secure belt mounting (can also be strapped on a canoe thwart or something similar) and provide excellent protection for your pistol.
After buying one from Dillon for my Sig 228 I had Wilderness make me a custom unit for my 629-2 Mountain Revolver round butt, fits it like a glove. I use that setup for mountain biking in remote areas where there's a risk of bear, big cats, and 2 legged coyotes. Very comforting to have, and if I crash on it neither the pistol or I will be worse for the wear.
The autoloader models carry one spare magazine in addition to the pistol, the revolver models accomodate 2-3 speedloaders in addition to the pistol.
-Eric