Open Game Art is a newly started site for exchanging free Artwork. While one can easily get the impression that there are loads of such sites around, Open Game Art is one of the very few that actually is done right.
As a Member of the Debian Games Team and the Unknown Horizons Project I was way too often in the need for good artwork searching around the web. I've also already reported once about my trouble.
There are quite some sites like Free Sounds around offering free artwork -- but only free as in beer as the saying goes, not as in speech which of course is really unhelpfull for FOSS projects. And even most of the sites that have free content often only tell you the license on some special pice of arts details page.
Open Game Art is quite different from that. All the license you may choose as a contributor are free (both in Debian and in FSF terms) and the license is available through a search filter so you can find stuff that fits you project's licensing policy. This list, and that's another thing I really like about that site, is the availability of choice among common licenses including, next to the copyleft class of licenses a fair share of more liberal licenses like my personal favourite, the zlib License.
And because such a site is just as good as it's amount and quality of data I've started sharing some recordings. I'm currently really new to audio recording so I guess it'll take some time for me to become really good. I'm considering putting some of my experiences and stuff I've learned here.