changing your identity

[sonearsofar]

I want to leave facebook, but have a private group I want to stay on, of which I'm the administrator. So how do I come back on with a different identity, as I would be using the same email address? Hope I'm making this clear...

you can change your name on facebook to something completely different and keep the same email address. However, unless you delete them all your old posts will still be on your profile with your old name - thus linking you to your old identity.
Alternatively create a new facebook account with a new email address (i use gmail) and join the group, then add yourself as an administrator before leaving with the old one.