When arguing with someone, say to them: "Listen you ignorant fool, you couldn't be more wrong. Go and look it up on wikipedia if you don't believe me". Then, without their knowledge, race off to a computer and quickly find the appropriate entry. Insert the "fact" you need to prove your point and you will win.
For example, I was arguing with a friend about which sport was more girly, soccer or touch football. To prove my point, I said that touch was invented specifically for girls to play. I then went onto wikipedia and altered this:
Touch started in Australia as a social "park game" as a training technique for rugby league teams during the 1950s and 60s.
Touch started in Australia as a social "park game", specifically to enable female participation, and as a training technique for rugby league teams during the 1950s and 60s.
(Ps, I've since admitted my scam. Besides being a fundamentally dishonest False Attribution, it was way too good a trick to not tell him about.)
Update (18th March): It's since been reverted back to the non-feminised history. It survived a bit over two weeks... not bad.