If I am going to a real knarly area (seldom), I take my .40 cal. pistol and a spare mag.
Yeah, good point. The EDC I described is what I have when I head to work. When I'm out and about anywhere else I carry a sidearm and one spare mag. In hot weather that's usually my Beretta Nano with a spare 8 round mag in a SHTF Gear horizontal mag carrier. Otherwise it's an HK, either a USP full sized 9mm or a P30S. In that case I'll have a spare mag either in a Safariland horizontal mag pouch of a Garrett K1 mag carrier. In SD we have CCW pretty much everywhere, and it's part of my regular CCW.
This is especially true when camping. I will usually have at least two spare mags when out in the woods, and sometimes a second sidearm.