Without regard to frequent flyer miles, the easiest way for an average person or small online business to accept credit cards is to use a service like PayPal or c2it. If you have a large business or you handle in-person transactions (eg. a store), you'll need to get a merchant account from a credit card processor. You can ask your bank for a recommendation (which often come with discounted rates) or try VeriSign.

As for frequent flyer miles, I'm not aware of any services that give you miles for payments you receive. You can set up multiple accounts and make payments to yourself, but this usually violates the terms of service of your accounts (and possibly your credit cards) and will subject them to termination.

[This message has been edited by ManyMiles (edited 05-08-2002).]