I carry concealed 24/7 - Kahr PM9, right rear pocket, with seven rounds of 9mm+P Corbon DPX in a DeSantis Nemesis pocket holster. I kayaked two miles on Jacobson Lake with it last night. It's small and light so I can carry it all the time, and the polymer and stainless construction is impervious to sweat and rain and whatever else I might encounter. It's also surprisingly accurate for such a tiny pistol, it has the sweetest DAO trigger I've ever felt, and I've found it to be extremely reliable. Them Moonies make a nice pistol!
I open carry mostly for educational purposes, because I don't want concealed carry to make guns "out of sight, out of mind" and perpetuate the anti view that only police and criminals have guns. My open carry is a Glock 20 (the mighty 10mm!) in an Uncle Mike's paddle holster. This was also my backwoods carry last summer when I went hiking and camping in Alaska because the G20 with Double Tap ammo (16 rounds @ 746 ft lbs of muzzle energy!) is the smallest and lightest weapon I had that would reliably stop a grizzly bear. For urban carry, 10mm can punch through a car door and still have enough oomph on the other side.
Lately, even when I open carry, I'm still concealed carrying the little Kahr.
I've also recently traded my little Buck key chain pen knife for a SOG Aegis.
http://sogknives.com/store/AE-02.html
I think I'm turning into a hoplophile.
http://www.urbandictionary.com/define.php?term=Hoplophile