There is a new website that offers FREE content for artists and game developers, FREE meaning that the content is licensed under GPLv2 or later, creative commons or/and other free as freedom licenses.
The goal of this website is to offer free content to anyone who wishes to use it, but it's mainly for games (although anyone can use it for whatever purpose).
The website offers 2D art (Texture, concept, portraits and more) , 3D art (models, many of which made with Blender) and audio (music, voices, sound effects and more). It also plans to offer articles and tutorials in the future.
You can use or donate (art or money) to this website so others may use your art in their projects : http://opengameart.org/