Facebook is down again, cause unknown
Update - 2:55PM PDT: Facebook appears to be back up--at least for us here in PCWorld's San Francisco offices. The Facebook Twitter feed notes, "Facebook may be slow or unavailable for some people because of site issues. We're working to fix this quickly." We're trying to get some more information, and we'll post an update as soon as we know anything more. Our story as originally posted follows below: