Music Archives
Creative Commons Mixter	http://ccmixter.org/
dMusic	http://dmusic.com/
SoundClick	http://www.soundclick.com/
OpSound	http://www.opsound.org/

Sample, Loop and Sound Effects Archives
Creative Commons Mixter	http://ccmixter.org/
Freesound Project	http://freesound.iua.upf.edu/
FlashKit	http://www.flashkit.com/
Findsounds	http://www.findsounds.com/
Ljudo	http://www.ljudo.com/

 

Recorded Audio & Famous Speeches
Michigan State Libraries - G. Robert Vincent Voice Library	http://vvl.lib.msu.edu/

 

Speech Synthesis
AT&T Natural Voices	http://www.naturalvoices.att.com/demos/index.html

 

Online Music Generators & Mixers
Wolfram Tones	http://tones.wolfram.com/