Sony Spyman™

How irritating is it when your on a bus or train and you can hear emanations coming from another passengers headphones?

You want to know what they are listening to, you can't just go over and ask them (unless you're a fruitcake, or some kind of special mobile music police that I have been hitherto unaware).

The answer is the as yet un-available Sony Spyman™ (Thanks to all for advice on little TM) Looks like a normal walkman/diskman, but incorporated a powerful directional mic that picks up the tinny beats, and comprares them with a large online database of possible songs.

The best way for the device to complete this analysis is probably to calculate the BPM of the music and then use this to refine its search. An extra function could be a fast search in real time of all local receveible radio stations, and comparision of their output with the spied-on beats.

Or maybe there's some other way of remotely analyisng and directly reconstructing the music your target is listening to. Eg monitoring the magnetic field around the target's headphones...