Turn Your iPhone into a Credit Card Terminal (CNNMoney.com)

For years, small business owner Pat Jackson struggled to find an affordable way to let customers pay for heating and air conditioning repairs with their credit cards at home.

The owner of Jackson Comfort Systems in Northfield, Ohio, once tried out a credit card processing service from Nextel, but her technicians hated the bulky phones it required. Then she looked into options from AirCharge and United Bank Card, but those services were pricey: up to $250 for portable credit card machines and $25 per month, per truck for wireless service.