(Business 2.0 Magazine) -- We all know the health-care system is a $2 trillion dinosaur of the way-old economy. So where's the opportunity in that? Everywhere.

But forget about trying to drag doctors, insurers, and hospitals into the Internet age. That was Health 1.0. Instead, if you're looking to start a health-related business, focus on the real customers - you know, the ones formerly known as patients.

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First they used the Net to educate themselves and shake up the medical establishment's Marcus Welby-era doctor-knows-best mentality. Now they're starting to control their own medical spending. Thanks to health savings accounts, people are moving over to "consumer-directed health plans" - you, the patient, get a health-care budget from your employer and manage your expenses accordingly.

That means you'd better shop around before opting for a $2,000 MRI.

Free to buy health care like anything else, tech-savvy consumers are looking at the next generation of medical services, everything from online genetic testing to Wal-Mart medical clinics. But as always, the real opportunity lies with services not yet invented. How about a Priceline for nonemergency surgery? Or an online reservation system for doctors' appointments, à la Open Table?

In the stories below, we'll show you where smart entrepreneurs are putting their money - and tell you what you need to know to get in on the action too.

• The Gene Screen Online genetic-testing services are springing up to take advantage of advances in genomics - and the growing willingness of consumers to conduct their most personal business over the Internet.

• Retail Therapy More people are adding health care to their shopping lists as walk-in medical clinics are popping up in Wal-Marts, drugstores, and other retail outlets.

• A Second Opinion for Medical Bills As the number of people paying for medical treatment through health savings accounts soars, software services that help them manage bills and spot errors are on the rise.

• Home is Where the Health Care Is The market for home medical monitoring for chronic conditions is taking off thanks to new interactive devices that remotely track patients at home.

• Steps to a Healthy Medical Startup We've identified ways savvy entrepreneurs like you can profit from Health 2.0. A hint? If you lack in-depth knowledge of the health care industry, don't be afraid to partner with someone who's got what you need. That's what AOL founder Steve Case did.