Pillow fight poster
A poster announcing the Valentine's Day Pillow Fight Club event in San Francisco. No organizer is listed on the poster. The event was organized somewhat like a flash mob: Word went out on e-mail lists, on social networking sites like Tribe.net and through general Internet word of mouth.
Enthusiastic pillow fighters
These pillow fight participants have no shortage of enthusiasm for the event.
The pillow fight crowd
Hundreds of pillow fighters have at it in San Francisco's Justin Herman Plaza on Tuesday evening.
Flying feathers
Countless feathers set loose from the battered pillows make it look like snow is falling.
Woman with pillow
A woman at the Pillow Fight Club event prepares to take down an opponent.
Getting pounded
Being in the thick of things meant getting pounded by pillows and inhaling feathers.
"Eat my polyfill"
One man uses his pillow to send a message to would-be attackers.
Cleaning up
When the pillow fight was over, the cleanup was only just beginning.