BTTW is short for: "Balls to the Whalls" means to go all out. It has been said that in ASL (American Sign Language) "BTTW" is said to be performed by the same posed used by commandoes in Contra 3 Alien Wars when you hold the "L" & "R" buttons down at the same time. This is a mantra chanted by those who recognize that the ideal represented in carnate by "Mark Whalberg" is the true path to awesomeness. When you are being so awesome you need to shout, and you just can't contain the awesome anymore, its a safe bet that "BALLS TO THE WHALLS" will satisfy that urge to rock on, and rock on hard.
*when you need a battlecry to rock out to:* "BALLS TO THE WHALLS!!!! or "BTTW" if you prefer brevity.