has a few tips about how to get good saving rates using current accounts:

High street savings accounts suck!

check the lloyds tsb section:
To be fair though, Lloyds does offer a cracking current account which some clever lovemoney.com readers use like a savings account. It's called the Lloyds TSB Classic account and it pays a truly fantastic 4% on balances between £5,000 and £7,000. The catch is, you need to deposit £1,000 a month to be eligible for the account, but you can get around this rule by immediately withdrawing this money or, if you're feeling cunning, setting up a couple of standing orders to send the money in and out each month. You can open up to three of these accounts at once, and the rate is fixed for an unlimited period even though you have instant access.

This may also work for Santander when you use their switch account: It pays to switch to a Santander current account

you could setup a £1,000 direct debit to circle between the accounts each month, if you set it to go into Lloyds TSB on the 14th of each month giving you 4% interest on it, then move it to Santander on the 21st giving you 5% interest for the period 21st till the 13th of each month, making the most of the extra 1% rate. The reason I suggest a week between the transfers is to play it safe for any delays.