USD/GBP exchange rate exposure


I live in the UK and have been trading index credit spreads for the last 12 months using my USD OptionsXpress account.

As ive transferred my GBP £ to USD $, I'm exposed significantly to exchange rate changes. Whilst in the last 6 months or so, this has worked in my favour sending money over to the US, I'm concerned about my exposure to the strong dollar when bringing money back to the UK.

Even though I'm in profit in my trading account, i loose a lot of this profit if i converted the USD back to GBP now.

How can i protect myself against this exposure?
Any thoughts on USD/GBP rates in next 3 months?

I want to set up an IB account in GBP and trade in USD as and when i need them...i wish i knew about this in the first place!