Hi Savage,
Bank wired $500 over to USA earlier this year and had just over US$1.63 to the UK£. Again changing a cheque from US Dollars into sterling last month gave the same exchange rate at the same building society (Nationwide).
Bank wires seem to give you a better rate of exchange than those you get at bureau de change.
Saying that the Post Office gives 0% commission and pretty good exchange rates on US$ (Travellers Cheques and Bank Notes). Changed £8000 into US$ and had US$1.62 to the UK£. Mind you that was back on the 1st July.
These .02 cent differences made quite a marked difference on the amount I changed, it'll make a massive difference on the funds you're changing! :-)
Best wishes,
Charlie Zulu.