Lenny Kravitz was walking down a New Orleans street when he heard a church choir singing one of his songs. Of course, he joined in and helped them out.
http://thebubble.msn.com/video/?id=92f6509b-5cf0-41d0-b9f1-13bfb49bdef8
I used to be a guard for DHS and we were taken in where they monitored Air Marshalls. They tracked every flight in N America, it was crazy to see how many thousands of flights there are at any given time.