Saving on currency exchange rates
 

How do I save money on currency exchange rates while traveling in Ireland and the United Kingdom?

Use a "no foreign transaction fee" credit card whenever possible or take money directly from a bank ATM using an ATM card from your bank that offers ATM fee reimbursement.

...and firmly decline if the merchant offers to charge you in Dollars rather than Euros or Pounds. Always insist that they process the charge in local currency.

Some people might also suggest to use a MC instead of Visa, but in my experience the difference is small enough that I don't think it's worth worrying about if you're just visiting. (Living there, on the other hand, might be a different story.)