Thanks for your participation
Well, it's (surprisingly) a very nice Gauss curve and the sample isn't small. There will sure be a systematic error, but you can compare the result with the best value you can honestly still give your dick.
Besides, I made the thread 16:00 central European time and there is an almost 1inch difference over the Atlantic according to some studies on the web
Why would they?
500 people will not all lie, but they might measure wrongly somehow. That's what I mean with compare it with your least honest measurement.
I'm 6'5 for one. And I test it repeatedly, for fun, if I'm in bed with a chick and a ruler is around.