The way I see it is this: using Twitter is like singing in the street for all to hear, whereas Facebook is chatting with friends in a busy shopping centre where any of your friends, family, neighbours and colleagues can overhear and you might not notice them listening. Email is a private chat if you can get anyone to leave Facebook for five minutes to talk to you.
Blogger is a private work of art and my work of art has been sadly neglected lately. The blogosphere used to be a secluded community as well but many of the residents have moved to Facebook and I can't be anonymous there.
So I've been finding my community in Ravelry, where I can be fairyhedgehogg and not worry that my colleagues and neighbours will be watching what I post. Plus I can post pictures of all my crochet works of art (and disasters) and know that people will be genuinely interested.
Meanwhile, out in meatspace I've been working, and crocheting, and even writing a teeny, tiny bit. And getting a new job.
Yay, new job!