[Boatanchors] OT: Microphone Point Source

[John Hensley]

A school teacher friend (non-ham) asked me if I knew where he could buy or getsome small microphones.  When I asked "how small", he said "Ideally they wouldbe very very small, almost like the points of a ball point pen".  NADA, says I.  Evena cell phone needs a diameter of 3/16 to 1/4".
But, I know very little about small point source microphones, if such a thing exists.
Has anyone heard differently on this?  He has written a computer program and inthat program, the microphones are mathematically seen as points.  I did try to bustthe bubble and suggest there was no such thing, but he is determined.  
Thanks for any suggestions.  Please send hate mail and Ga Fawrs off the list :-) ..
John W5JV