I have a bunch of collapsed emails, and I wish to seperate them, how do I go about doing that, so that I have 1 email for each message?

Do you mean like this?
http://img53.imageshack.us/img53/2885/gmail14fv.png
I don't think you can separate them...

You use Gmail, I suppose. Download a mail client like Thunderbird or use Outlook Express.
http://mail.google.com/support/bin/answer.py?answer=13273