Creative Commons - Get Creative
Common Craft Video: Copyright and Creative Commons
Music dig.ccmixter Jewelbeat Free Music Archive Youtube Audio Library (and Soundeffects)
Audio Sound Clips Soundbible incompetech audiojungle ($) neosounds ($)
Images
Compfight or Flickr Advanced Search: photos, videos
Google Advanced Search: for usage rights, choose "labeled for reuse"
Description of the CC Licenses
Cogdog's Flickr Photo Attribution