Discerning TV viewers might notice a recurrent theme on their favorite shows this week. The doctors on ABC's "Private Practice" give homeless teens free checkups. On NBC's "30 Rock," Kenneth Parcell tries to adopt every dog at a shelter. And two characters on CBS' "Numb3rs" discuss joining Big Brothers Big Sisters. The outpouring of volunteerism is no coincidence. Rather than just "running a bunch of stoic PSAs," media executives of all major TV channels came together to embed messages into story lines. It's an unprecedented call for service.
