Brand Resource is probably a good start:<p><a href="http://www.facebook.com/brandpermissions/index.php" rel="nofollow">http://www.facebook.com/brandpermissions/index.php</a><p>"You can make a reference to Facebook (online and offline) to describe your presence on Facebook and your use of our products and services. Your reference must be truthful, and cannot suggest that you are affiliated with, sponsored, or endorsed by Facebook."