Flashmobs are short, seemingly spontanous aggregations of people on public and semipublic places. They are oranized via Weblogs, Newsgroups and chain-emails and dicicively do not stand for any political content.
Following a call from the internet the participants meet in a place where they receive further instructions on the place the event takes place and the expiration of the flashmob. Typical for flashmobs are the sudden creation of the mob out of nothingness, the ident performance in the mob (i.e. applauding, telphoning using identical text) and the sudden nulification after few minutes.
Beginning from the day of a first action in New York in June 2003 the flashmob wave arrived in Europe in the end of July where first actions took place in Rome and Vienna
Related Ideas that comprise of groups of people working toward a common goal:
Also see: FlashMobWiki