Speaking a text message out loud as you type it.
Pretending to write down information, like a phone number, that someone is dictating over the phone to you.
Moving your mouth as though you are reading the lips of the person who is speaking to you.
Ordering menu items in a Mexican restaurant with a Spanish accent- even when you know no Spanish.
Using caulking guns to dispense sour cream (usually at Taco Bell, but I am sure they must do this at other restaurants.)
Looking up and down the street before picking up your dog's poop as though you are contemplating leaving it if no one sees you, or don't want anyone to see you doing an unseemly task. Or maybe you want someone to see you being a good pet owner and picking up after your dog- someone should stand on the sidewalk and clap for you.
Taking a tiny pair of scissors out of a purse and clipping off split ends while waiting in line.