For people who do not have a fixed office and provide a service collecting payment has always been something of a chore. These are people like appliance repairmen, personal trainers, car detailers, limo drivers, painters and electricians. But thanks to the same technology that allows people to make mobile phone calls from just about anywhere those on the move professionals can now do the same thing with wireless credit cards. They can process payments in real time and even give their customers a printed receipt.