Where do you exchange your sterling for dollars about? - where is the best exchange rate at the moment?

What ratio do you go for with regards to cash and travellers cheques?

Thank you, everyones help in answering all my questions has been a godsend

On average if we pay for themepark tickets before we go, how much would you recommend we take for 18 days? (Cleared crdit card in tow[msntongue])