iPad-based EMR pioneer Dr. Chrono recently announced that it now allows healthcare providers to accept payments from patients directly on their iPad. They uses the Square dongle to do this, which supports credit cards. It is a very interesting move as it integrates more and more traditional practice management features into the iPad EMR. That allows the doctor to be more mobile. Imagine that a doctor and nurse practitioner making house calls, and be able to accept patient co-pay right there in the patient's home.
Of course, while convenient, Square is an expensive way to accept credit card payments (due to its fees). But with more and more competition entering the mobile payment space, we expect to see cheaper and potentially better solutions soon!