flash mob
(FLASH mawb)n.
A large group of people who gather in a
usually predetermined location,
perform some brief action, and then
quickly disperse. —v., —adj.

—flash mobber n.
—flash mobbing pp.
(quoted from the original on wordspy)

links outside (sites)
"Smartmobs"
flashmob.com
SYDMOB
melbourne-flashmob
flashmob-dev
flock smart
flashmob.info
Mob(b)log
flash hack

links outside (articles)
Melbourne's First Flashmob | 21.08.2003

links inside (stuff)
SplaTT's moblog
SplaTT's weblog

2005 Australian Blogging Conference