Another vote for Propay here.
Easy to use, 60 dollars annual (not monthly!) membership fee will allow you to process 3K per month in transactions.
The only other fees are 3.xx% plus 30 cents per transaction.
I just referred a family member who is a small business owner with truly HORRIBLE credit (his personal CK score was below 500 when we ran it) - and he was approved for the 3000 per month account.
If you need to process more than 3K per month, the approval process will be different and your personal credit may come in to play.
Propay is now offering a card reader too, for 99$ one time plus 4.95 per month (waived for the rest of 2008, I believe)