sPy *TIP*: it's not important what you actually say. no one is paying any more attention to what you're saying then you are to their response. the key, or *TIP*, is to just finish what you're saying as quickly as you can, and while you're finishing, to chuckle. when they respond, chuckle again and use either a "definately", a "you never know!", or a "yup, I hear ya!" in your response.
sPy *TIP* #2: when you see subject of short convo approaching, grab cell phone out of pocket and open it/stare at it intently as if something very urgent has come up. "Hi Al, how are you?! - OMFG, I'm late for this conference call!!!111"