Are you serious about winning pillow fights? Matthew Borgatti is, so he made this mace-shaped pillow for an upcoming flash mob pillowfight in New York City. He writes:
Surprisingly it took a good yard of cushion foam and two bags of poly-fill to do this one up right and get it nice and spherical. In other interesting news this may be the first dodecahedron I’ve ever constructed.
Link via Super Punch
"A flash mob (or flashmob) is a term coined in 2003 to denote a group of people who assemble suddenly in a public place, perform an unusual and sometimes seemingly pointless act for a brief time, then disperse, often for the purposes of entertainment and/or satire. Flash mobs are organized via telecommunications, social media, or viral emails" -wiki
So... yeah, preparation for a flash mob is relevant to the mob's goal.