If you have an annual turnover of less than $500K, then you have 2 options, one that will cost you on fees and rates of exchange:
I see that a few alternatives were mentioned above including Paypal and a Brokerage house. These would have been mu suggestions, Paypal will smash you on the rates of exchange and the fees when receiving payments, a normal broker would try (for the sake of having a new client) gather all your payments in and build it up and convert at your convenience at a much better rate. However, the danger is that when you're not looking (believe me, they know when this is happening) they will actually become more expensive than paypal or any other bank on the High Street.
So what to do? You should take advantage of the crisis in Europe to benefit from it. Call countries such as Portugal, Greece and Italy and open an Euro account as well as USD account. Once this is done close the Euro account and simply run the USD account should you wish.
I have actually opened my Business Euro account with Caixa Geral de Depositos in Madeira Island, they will only charge you a standard quarterly charge of around €10.
Compared to the UK where Barclays wanted to charge me every time money was credited to my account, quarterly charges and a huge charge on outgoing payments and yes I do well over 500K per annum, but still not worth it. When it comes to USD thigs get even crazier.
As you may know there is no such thing as BACS in the US, everything runs via a similar system to CHAPS. Barclays actually wanted to sit on my funds for a day or so and for the type of business I run, this is mad!
European Banks are willing to attract more clients, and they are actually prepared to offer great deals and everything can actually be negotiable. Give them a try and see how it goes...
For the amounts you do, believe me this is the best option!!