When deciding what pocket revolver to purchase a few months ago, I went to a friend (on THR, Action_Can_Do) who owns a 3 1/8" SP101. I tried it out in the pocket, but I was less than pleased. I settled on a 642; it best filled the role I wanted. There was also a Taurus (650?) that was just as good. Also, last week I received the Desantis Nemesis, and that has turned out to be a fine holster. Without one I was uncomfortable with the gun moving around in the pocket and with the possibility that a hole could develop in my pants over time from parts sticking out, especially the barrel (a common problem of pants that I own and keys I used to carry).
SP101 for pocket carry? Works for some, not for others, but definitely worth a try.