I use a Blackhawk pocket holster for my S&W Airweight 442. Secure fit and an easy draw.
I sometimes carry a S&W 638. I use one of three methods:
1.) Kholster inside the waistband holster (similar to a Crossbreed Super Tuck)
2.) Galco Ankle Glove — by most reports, the only ankle rig worth buying
3.) Desantis Nemesis sleeve (I usually just put it in my back jeans pocket with an untucked shirt covering it).
With a pocket holster, do you need to be careful about the pants you wear? I could see it being uncomfortable in jeans, but not so bad with Dockers or slacks.