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Imagine hearing such a fantastic track on the radio that you want to dash out
and buy it—only you don’t know what it’s called. Why not let your
cellphone tell you, says Bill Poel of Chelmsford, Essex. In W0 00/57586, Poel
notes that CD players can already identify CDs using inaudible digital codes. If
those codes were converted into brief audible bleeps at the end of each track, a
receiver built into a mobile phone—or a PDA—could pick them up. The
phone will always show the title of the last track heard.