Hmn - postgraduate work seems to be a common answer to the 'What do I do now!' question. I almost went and did a postgrad myself and the basis that I hadn't (and still don't, really) any idea of what I wanted out of life.
No real answers, I'm afraid. One day I decided that I'm going to want X! And set out to acheive it. I don't know what i'll do when I've managed that, although several of my goals are likely impossible and so I'll never have to give up trying to achieve them and I'll never be bored whilst I'm trying.