I came across the Audio Archive yesterday while searching for information about the pronunciation of English dialects.
The archive is part of an newsgroup about English and contains recordings by English speakers from around the world of a number of different texts.
Other collections of English dialect recordings including the British Library’s Sounds Familiar? and Archival Sound Recordings, the BBC Voices project, Sound Comparisons, the American English Dialect Recordings at the Library of Congress, and the International Dialects of English Archive.