I love when students get calls in class. The first time I hear a ringtone or vibration, I sprint to the student and insist to talk to whoever is calling. This is all presented playfully, as a gag. "I wanna talk! I wanna talk!" They're usually so surprized that they'll either mute the phone or actually let me answer. When I do get to answer, I usually answer with "Atlanta Police Dept. Zone 6, this is Sarg. Whatever." Always gets a laugh and the phones are silent for the remainder of the term.