It's been quite some time since I've linked to James Lileks. Deficiency corrected: "Simple Rules for Making a Fool of Yourself on the Internet".
Swear angrily. Not just the classics, but the ones relating to excretion and genitalia. Nothing shows you're a serious thinker like a torrent of obscenities. It's the reason Courtney Love is invited to speak to the U.N. so often. Added bonus: Lots of cursing means no one will suspect you're a Christian.