As an early-morning follow-up to yesterday evening's post, I should point out the British Library's Archival Sound Recordings Project, which, as a pilot program, has set a goal of digitizing 4,000 hours of audio recordings, and making them freely available to educational communities in the U.K.
The project is funded by the Joint Information Systems Committee (JISC), which interviewed both the Head of the Sound Archive, and the Archival Recordings Project Manager back in 2005.
Sample audio from the Sound Recordings Project includes the poet Simon Armitage reading "Entrance," Tolstoy's Waltz in F, and the call of the Tawny Owl (all links to Real Audio files).
The full list of audio samples is on the project's "Listen" page.