Kottke has already mentioned this list of extraordinary audio recordings, most notably the only known and authentic recording of a Castrati - a man castrated at an early age to ensure a singing voice unchanged by puberty.
What hit me from this list was #7, a recording of Florence Nightingale from 1890. While listening to the recording, I remembered that a wrote a research paper on Ms. Nightingale in elementary school. How times have changed when I can dial up an almost 120-year-old recording of a notable, historic figure.
Also exceptional was #6, the recording of a ‘Number Station’. The mystery surrounding Number Stations is strange, not to mention it’s obvious influence on Lost.