Users of Internet Explorer 6 have an average IQ score barely more than 80; Firefox and Chrome users fare much better, with average IQ scores of around 110, while Opera and Camino users have an average IQ score more than 120.
Got it from a friend that's forced to use IE6 at work. Seems fishy. Not sure I believe it, but it's funny. And if you use IE6, please upgrade now. Yes, now. Stop everything and do it now. Now.
UPDATE: I was suspicious of this one at the time, but I thought it was too funny to pass up. It turns out it was a hoax. But I still think it's funny.