they call that binaural recording, don't they? i believe you can get dedicated mic sets and even dummy heads with the correct mass and density, i.e. the same as a human head. Brendan O'Brien, i believe, uses the technique quite a lot, hence the Pearl Jam album Binaural which he produced. seem to recall reading an article about it in Sound On Sound magazine a few years ago.
unfortunately i'm one of those people for whom it doeasn't quite work. that barber shop clip is amazing! but when he moves around the front i percieve him as passing above my head between my ears. apparently some people just can't "detect" the forward sounds in a binaural recording. :( apart from that, fabulous!vv :D