In reply to djwilse:
100% get the Halifax Clarity I've been using it for about 5 years in countries all over the world and it's the simply the cheapest (by far) and most efficient way of getting money abroad.
With respect to the ATM charge, the vast majority of ATMs in the world I have used don't charge you anything, but occasionally, ATMs (and even chip and pin machines in shops/restaurants) offer to give you the (for example) 100EU at XYZ rate which will cost you £95, but there will always be an option to just take the 100EU instead, and the rate (determined by Mastercard on a daily basis here: https://www.mastercard.co.uk/en-gb/consumers/get-support/convert-currency.h...) will always be better than the rate offered by the ATM
I presume some ATMs just like in Britain charge a few $$££ to use but I think you'll get that anywhere if the shop/hotel owns the ATM and decides to charge.
I actually used the clarity card to transfer £1,000s to Australia when I moved there for a year, by withdrawing the max everyday and paying it off with online banking, as the previous poster says this cost me pennies to transfer several grand, you would be charged £10's to use a proper forex transfer company/service/bank.