Confessions are a great source of content and work well across many formats. Study the details on how to execute a Confessions segment here, then listen to this example of DeDe In The Morning Weekend Confessions
The short story is that listeners call in to confess something that happened over the weekend on the air. This is an effective Monday morning segment to get the phone ringing, but you probably should arrange for ringers or set up calls to launch quickly with one or two strong, provocative responses. This usually opens the floodgates. The sooner a great confession or two is on, the better the response.