A very interesting piece from Motley Fool on the problems at Northern Rock, http://www.fool.co.uk/news/your-money/2007/09/14/northern-rock-a-busted-bank.aspx?source=ioowftxt0010011.
It's certainly worth remembering that if a bank does go down individual are only insured under depositor protection for £31,500.
Hopefully a Bank of England rescue combined with a potential sale of the business might halt the flow of deposits out of Northern Rock because if it does continue then it could get quite nasty.