Social media sites about OA

"The Open Access Directory just launched a new list of social media sites focused on open access to research. This version of the list covers Facebook, Google+, Linkedin, and Twitter. OAD is a wiki and depends on the OA community to keep it current and comprehensive. We launched this list when we had a critical mass of entries worth distributing, but we're sure there are many more out there. Please help us add the ones we're missing...."