I just signed up with c2it (
www.c2it.com) which is run by Citibank. It allows you to accept credit card payments without having a "merchant account." It will probably be a fee-for-service process for the payee in the future but it will probably be less than the current credit card system and I don't intend to charge the fees back to my guests when and if that occurs. The downside is that the payor must also sign up (but its quick and easy and free).
I wasn't able to accept credit cards before because I could not get a "merchant account" from a bank for private condo rentals, and the other kinds were prohibitively expensive but c2it works great. It also works with bank accounts as a way to send online payments even if you don't have a credit card, by the way.....
It does not work as easily if you don't havce a US based account.