Laying shirtless on one's back and placing an ice cube in one's belly button. Thought of as clever by trailer trash from the Southern United States. Only effective when the user posesses a ponderous beer gut.
"Earl! Why you layin' all up in the hot sun like that?"
Urinating in an open container while riding in a moving car. The phrase originated in 1835, when settlers riding the Oregon Trail were forced to relieve themselves in a large Stetson hat, to avoid stopping their wagons for fear of Indian attacks.
"Geez Jimmy, would you drive a little smoother? I'm filling up the stetson right now, but since you're driving like a maniac, it's splashing around everywhere."