There's a fine line between being charmingly talkative and being a blabbermouth: you know how to walk that line, but not all people do. Keep an eye out for a friend or coworker who isn't watching what they say today. Step in and help either prevent them from putting their foot in their mouth or (if you are too late), help them dig themselves out of an awkward hole. Your quick thinking and quirky wit can help everyone move forward to better topics and better ideas.