Goto: http://wistia.com/about/yearbook

And click "Party Time" down the bottom.

A fantastic bit of personality.

(And yes, for hair-splitting and the pernickety, its not exactly an 'easter egg' - i.e. its not that secret / obscure).

PS: Best easter egg I've ever seen: created by a disgruntled programmer working at an ad agency, for a pizza website, when you clicked a series of dots on the side of the page, in a particular order: you got a dancing gimp take over the page --- terribly unprofessional, but quite an hilarious easter egg.