4 people to form a firemen's line of "stuffers", 1 to measure dialation, and 1 to film the whole flithy process?
That might be a little too 'in your face' (or ass, as it were) at the very beginning, but maybe for a 100th post activity?
Also, we could offer an airline mileage rewards program. After so many "Howdy Miles" have been racked up, say 75,000, you get a colored user name for two weeks.