I've gotten other tells before from people who didn't know you could fish while sitting down. (Well, standing there all day would be tiring, wouldn't it?) Or from people who didn't know that hunters could feign death while disguised as just about anything. (Remember that rabbit buff from the Blossoming Branch? Try turning a hunter into one and asking him to feign death.) Or that the Celestial Steed will turn into a bizarre, blood-red beast if you ride it while you're under the Animal Blood debuff from Borean Tundra. Or that even druids in cat form can blow bubbles with pink gumballs!
Do you do anything that prompts people to say "How'd you do that?" Do you know of any unique or strange effects, transformations or other fun things in the game? Have you seen someone do something odd and wondered how they did it?