Oh my, yes! I co-GMed a gang-style RP with a close friend back in the day. (And participated in numerous others. I also wrote a gang story by myself once... hehe.) If you'd like some ideas or whatever, feel free to send me a PM! I'm on winter break now, so I have a lot of free time.
(Reference the Angel and Knox quotes in my bio... They were from a gang RP lol)