Yes, it's set daily by the BBA (British Bankers Association) based on what a sample of leading banks say it is costing them to borrow on interbank markets. As I understand it, the CDS spread is also added to the cost of borrowing (this is the cost to insure the lending), so Irish banks (which have high CDS spreads) are paying more than, say, Barclays (which is seen as lower risk) would. Again as I understand it, the problem with the credit crunch isn't that there is no money being lent, it is that the cost of this money is prohibitively high so banks are unable to get economic money to lend (they can't make a profit on it).
For comparison, Euribor was about 0.1% points higher than ECB rates before the credit crunch, it is now more than 1% higher - see the comments on this page from finfacts:
http://www.finfacts.com/Private/dbn/dbn.htm