So often, it takes an outside force to generate change. Take the business of medicine in the United States, for example. It's been stagnant for too long, and it doesn't really work for patients or doctors.

But a new change is being driven by nurse practitioners. They're the ones who brought us "nurse-in-a-box" practices that are open 7 days a week with extended hours for basic medical care. That means shorter wait periods. You'll typically find these practices in big box retailers, drug stores and supermarkets.

The nurse-in-a-box practices are upfront about their pricing, with brochures or charts that detail every service along with the actual price -- much like a menu at a restaurant. In addition, they keep records electronically. Clark laughs whenever he's at a traditional doctor's office and has to fill out a piece of paper on a clipboard. Come on, people, this is 2008!

This is a great example of medicine responding to the free market -- though it's not a knock on doctors. You have to realize that our system is set up with medical school being so expensive that young doctors can't afford to go into general practice. So the nurse practitioners serve a very valuable function.

However, there is one major problem with the nurse-in-a-box practices. There's no continuity of care. They won't know your medical history like a primary care doctor would.

The Kansas City Star reports that primary care doctors are feeling the loss of revenue from nurse-in-a-box practices and making some adjustments. They're offering better access, including evening and weekend hours. One practice saw a big increase in both patients and profits as a result of the changes, according to the paper.