A simple phrase connoting the desire or need to depart from the current location; usually followed by a response of "Let's roll." The importance of such an action can be magnified by the individual orating both portions of the clause as in "Nine-Eleven; let's roll."
Approaching time to go to class
Gentleman 1: "Nine-Eleven?"
Gentleman 2: "Let's roll."
At a horrible party
Gentleman 1: "Nine-Eleven; let's roll."
Gentleman 2: nods in agreement