I haven’t seen eFax type services on social networking sites. It would be nice to receive faxes on your personal pages. It sounds like a genuine necessity. Although that pushes social networking towards communications more, but that is going to happen eventually. You are likely to have your mails being ported on these sites through simple popmail readers. In fact I would be surprised if there is no popmail reader available as an application on Facebook etc. And that pops up another idea. Let me post that after this one.