Not sure this is the right term... Back on my old phone a Verizon rep called me back and pushed a ringtone to my phone - overriding my ringtone with the one he sent.
At the time it was summer and I was sitting in my car. Not recognizing the ring, I thought it was the guy in the car next to me. I thought he was pretty dumb for not answering (!!!).
However, now I think this could be useful. If he could do it, is there a way for us users to do it???