Flashmobs Everywhere

A checkin based system, possibly an application, which coordinates random action.

The object is to coordinate ad hoc flash mobs between strangers by accepting location based check-ins and when there is a critical mass of people checking in within a few blocks of each other, coordinating group action by telling all of those who have checked in that they should appear at a certain specific location with an action for them to perform. The locations would be randomly selected from "nearby" locations and the actions would be pre-populated and selected at random.

I expect this would find use on college campuses and anywhere people want to have fun.