For all you experienced homebrewers out there, I was wondering what bacterias or yeast strains did you use to get your beer sour. When I say that I mean you were trying to make a sour beer, not it soured because of the bacteria or yeast.
If you're interested in producing sour beers, read American Sour Beers by @OldSock and it will likely answer all of your questions, as well as a host of questions you probably haven't even contemplated yet. His blog is also a fantastic resource to learn some basics before you decide if you want to dive in. The short answer is that both of the major home brewing yeast companies (Wyeast and White Labs) produce a few yeast/bacteria blends, The Yeast Bay has recently gotten into the space with a sour blend and a variety of Brett blends, and pitching bottle dregs from sour beers tends to help increase biodiversity on top of the commercially available blends.