I don't take credit cards. But it may cost me some small percentage of business. Of course, you also have to pay the credit card company some percent of each sale, so it could be a wash.
This is the way to do it. No monthly fees, you can accept all major cards and custys think it's cool!
You do need a smart phone to use it. They send you a free card reader that plugs into your phone. Transactions are fast and easy. Intuit offers a similar system that links to quick books I think.
I don't do a lot of cards but I like to make it as easy as possible for people to give me money. I lose a little with the transaction fee but I think it's worth it.