The idea of smart mobs came from politics: They were ad-hoc groups of demonstrators who used mobile devices to help co-ordinate their movements. Now there’s TxtMob, an SMS tool designed specifically to connect protestors of the Democratic and Republican conventions. According to a recent posting on a mailing list, it seems to work; a member of the protest Black Tea Society wrote:

“TXTMob was great! When the cops tried to arrest one of our
people, we were able to get hundreds of folks to the scene within
minutes.”

(Thanks to Smart Mobs for this one!)