Okay, this one's old news, but it's something you should hold close to your heart, not just read and dismiss. It's Scott Adams's Dilbert Fallacies.

Take this link, print it out at 25% size, and keep it in your wallet or purse. Keep it with you for a week, and check them off as you see each logical error applied around you. See if you can collect all 32!

Here's one to start you off: "I didn't get caught jaywalking today, therefore it's legal. to jaywalk."