Do you have an Iphone, Ipad or Android phone? Check out the Square! This great little gadget allows you to take credit card payments. Signup is free and there are no monthly fees. There is a 2.75% transaction fee instead, which is much more feasable for those of us who have sporadic sales. It's a great little tool to have at shows.
You simply download the mobile app, complete the short signup process, link the square to your bank account and within a few days, you'll receive your square in the mail. It's only about an inch square (hence the name) and attaches to the top of your phone in the headphone jack.
Here's a link to find out more info.