http://www.edgehill.ac.uk/tld/studen...ssertation.htm
A friend who's a senior university lecturer in creative writing suggested a way of overcoming writers block. Simply write constantly for 10 minutes (you can increase this to 15 or 20). Just write everything that comes into your head. Don't stop writing at all until the end of the time period. If you can't think of anything to write, just write 'blah blah blah...' until the words start to flow.
At the end of the time period, you should hopefully find some decent sentences in your 'stream of conciousness' that you can expand on.