Has anyone ever used LibraryMixer? It's a new site a really good friend just launched that has 4 functions: One is informative (like a wiki page) you can contribute to, another one is discussion based (like about new media or a new band you like) but also post reviews like yelp, one is a social network that is completely private (with an open source chat function to chat and share files) and a library (to keep track of music you have or you want).
A video is here: Protected content ...
You can access the site at librarymixer.com
The Alpha Invite Key is: Nekothecat
The alpha phase is up on for a limited time so be sure to sign up first so you can be noted as one of the first users before the beta phase comes out!