If you're planning to go to the dam or anywhere else that uses euro anytime soon then the best place on the market to change pounds to euros is http://www.travelex.co.uk u need to order online and collect at a branch. i got 1.02 euro to the pound on Tuesday (yes it sucks but its the best rate out there).
Dont know if its best for changing other currencies to euro though.
TT
:edit: Now getting 1.07 euro for the pound.... ''GUTTED''
Im £20 quid down now