It's called Practice Fusion, and if you can tolerate some ads on your screen you can use it as a software service free of charge.
Chris Anderson of Wired calls this the "Google Model" having coined the term "Freeconomics" to describe the result. (Personally, I think it's just open source and Internet economics in action. But his bank account holds more zeroes than mine.)
On his own blog, Healthcare Epistemocrat, Brent Pottenger quotes from Anderson at length, but the business model stuff is key:
Financially, Practice Fusion derives revenue from similar sources as Google does: by embedding advertisements in a banner at the bottom of its electronic medical record system and by selling anonymized patient and doctor data from its system to third parties, maintaining HIPAA compliance along the way.
Doctors can opt-out of the ads for $250/month but few do.
An EMR system is the most expensive upgrade a medical office can do, and given that they're given all the financial risk but few of the benefits, most small practices choose not to.
As a result of this, gross statistics on primary health care are very difficult to compile, mistakes are made due to bad handwriting, and the U.S. healthcare system falls further-and-further behind.
But it doesn't have to be that way. A doctor who wants to invest some time in getting existing records online can use Practice Fusion free of charge.
ZDNet Healthcare has been offered an interview with PracticeFusion CEO Ryan Howard and I hope to talk with him soon. Feel free to leave your own questions for him in the comment thread.