It's been a while, but I've done it a few times, a 3" 65 strong-side IWB and a 642 weak-side pocket carry, with a speed strip of .38 so I could reload either gun if need be. I've also experimented a bit with carrying a pair of J-frames (a 642-1 and a 642ND) in the same manner, but not for any length of time.

My problem is that I'm one of those guys who has a bunch of cra stuff in my pockets, so figuring out how to carry it all with 2 guns, without resorting to a fanny pack, has been difficult.

Plus, for my typical attire (I practically live in jeans), pocket carrying a 642 isn't exactly "optimum."

I am a fan of having a gun accessible to either side. Unfortunately, lack of shoulder mobility makes support-hand drawing from my strong-side holster nearly impossible with my current set-up (Beretta PX4 Compact in a TT Gunleather Mike's Special IWB holster). It also makes using a crossdraw holster difficult. One thing I liked about carrying a 642 in a Side Guard Holsters Quick Clip IWB holster, that extra play on the belt made it possible for me to do a support-hand draw because I could reach the gun and pivot it in the holster and draw it out.

So, for now at least, I carry one gun at a time on me. But I see nothing wrong with carrying a back-up gun. How many people are willing to drive around without a spare tire?