Hey guys, I found a website I while ago where people post art, sound effects, and music for people to use for their own games for free.
Some art and music require you to credit them and other things. There was an old forum post about it but it hasn't been posted to in for 3 years. It's quite popular, and you can post your own art/ request art. A lot of the art is stuff people used for their own games an want to give away for free
Here it is: http://opengameart.org/
Here is a video about it: http://www.youtube.com/watch?v=BCopHeE6j2w