Tools: Organizing Audiences

Mike Hedge pointed out to me that we now have a major distributor using Eventful to organize screenings on a local level. Back when Adventureland was released, I few fans found me to let me know that they had organized screening groups on MeetUp. Both of these are powerful tools, that the indie film community needs to make more use of.

And of course, let's not forget where we first heard of this sort of thing. Arin & Susan paved the way for Dreamworks... ?! Let's make sure this kind of thing becomes an indie filmmaker staple.
Imagine that when a filmmaker announced that their film is going to debut at a major film festival, that in addition to launching their trailer and going into a new phase with their blogging they also utilized these tools to aggregate audiences on a local level. There might be a film that was able to go on a tour immediately following the premiere taking the work directly to the core. I wonder what sort of impact it would have with the old school distributors to hear that a filmmaker already had thirty or more dates that the fans themselves requested.
Filmmakers could motivate fans to organize these screenings and to recruit audiences by offering a wide variety of incentives from exclusive music downloads to Skype Q&A's afterwards. Film clubs could easily do the same. Heck, so could distributors. We have an Indie Film Promotional Army out there, already armed, and waiting for the call.
When I look at the number of tools we have at our disposal (check out the list on the right to start) that filmmakers are still underutilizing, I feel like we have all been given crate loads of matches but we still all live in the Dark Ages.
I would love to hear of some filmmakers direct experiences utilizing these specific tools.