Sunset Park Chronicled has an excellent run-down of how the Gang Awareness Forum, hosted by the 72nd Precinct, went.
I'll use this as a reminder that anyone who sees gang graffiti should call 311 to report it for clean-up. The huge gang graffiti at the front of the 44th entrance to the park last year was painted over in record time. However, lesser known groups' graffiti remains for months. If you see graffiti that has a single line through it, chances are that's one group "canceling out" another's tag. The more often we call in graffiti like that (or all graffiti, really), the less often it will happen in the long-run.