Creative Commons Files

Besides jamendo.com, I used beatpick.com for creative commons audio files. You have to provide an email, because they send a link to the file download (and direction for attribution), but they do not send spam mail and it was quick and painless downloading the track.

I googled creative commons to find other sources and other types of files (photo, video...).
Rather than post the many sources I discovered, I will just provide a few searching tips:
Search creative commons and add the words audio or video or photo to find other sources

If you will be doing many projects and want unlimited choices, contact ASCAP, BMI and SESAC. They are the three largest music publishing companies in the world. Most of what we hear on radio, TV, film, commercials... is licensed through these companies. It will cost an annual subscription fee (for non-commercial purposes, I think it starts at around $300). I personally would love this freedom of choice, however I do not produce enough video to justify it.