The Chelsea building society have a 1 and 2 year fixed rate bonds paying 6.60% and 6.30% (gross) and they do a tracker bond paying 6.60% (1.60 above base rate + 30 days loss of interest until 17th March 2010).
A good thing with the the Chelsea is that with all their accounts there is a monthly interest option which you can choose and if you don't want the monthly interest payment you can leave this to roll up in the account and when you want it you can instruct them to pay it into another account.
However, I prefer competitive** instant access accounts, so I have Chelsea's Rainy Day Account paying 6.10%.
http://www.thechelsea.co.uk/savings/index.html** I look to get a good rate for my savings, but I will not put it into an account just because it has a very high rate. In this climate when I see a bank or building society with a very high rate this starts to ring alarm bells.
As well as spreading my money for safety, I keep a fist full of gold sovereigns in my own personal central bank.