Is anyone gonna send these in? I think ‘a whored of prostitutes’ would take off.
A historian used to know, Clive Holmes, suggested “a malice of historians.” Very appropriate, and I think it might even be extended to “a malice of academics.”
a babble of blondes
A Collective of Trekkies
A massive of MMORPG players
A snarl of Order of the Stick fans
A legion of demon worshippers ( "my name is . … " )
A gaggle of Gs? 
EDIT: Shit, is G the letter a noun? What if I say “What up G?” 
This thread boiled down to geekiness and sex in record time.
a nuisance of mimes
a matrix of mathematicians
a groan of comedians
a nebula of astronomers
a kernel of webmasters
A cat-o-nine-tails of dominatrixes (that should be dominatrices, I think)
A Campbell of science-fiction writers.
A shitload of nappies (diapers)
A flock of wallpaper designers
A number of anaesthetics
A gagglefuck of new guys.