As the guy above says, use Nationwide. Most of the heavy business travellers in my comapny do. I have a Nationwide current account, and use a debit card for cash withdrawals. No commission, interbank exchange rate from just about any ATM. Also have a Nationwide credit card which I only use abroad - again, interbank exchange rate. Don't use a credit card for cash advances - you get hit for interest charges.
Most credit and debit card providers take 2.75% on every transaction via exchange rates: some hit you for commission as well.
There internet savings account is pretty good as well.
They are one of the few remaining mutuals, and long may they remain so.
Most credit and debit card providers take 2.75% on every transaction via exchange rates: some hit you for commission as well.