http://www.improveverywhere.com/2006/02/18/cell-phone-symphony/
A cacophonous prank worth of the name Cacophony
Once everyone was in the store with their bag checked, I called our conductor Agent Kula back in Union Square and told him it was time for the first movement. He counted down and had all 60 callers hit send simultaneously.
At once, the phones started ringing in the bag check. In addition to the pre-set groups of phones, there were many more random ring tones firing off in a maelstrom of high-pitched beeps. The primary audience for this mission was the Strand employees, specifically the two who were working at the bag check.