On tiny keypads and greasy touch screens, doctors, nurses, NPs and physicians assistants these days are doing a lot more than checking email and phone messages. Increasingly, health care workers are using their iPhones and other smart phones to track patient information, take vital statistics and even make clinical decisions.

Just months after the first iPhone was released, technology message boards were abuzz with discussions about how to use the new-fangled phone for medical purposes. Many professionals were anxious to start tapping away on popular programs such as Epocrates, an application that had already been around for nearly a decade via the Web and PDAs to help doctors track patient data and treatments. Today, according to the company's Web site, about one in three U.S. physicians are using the programs on mobile devices and online. And some 1,500 other medical apps for doctors and other health care workers have followed suit. (Eager iPad-owning MDs might have to wait a bit, however, as a recent review from iMedicalApps.com noted that although the new device fits in the pockets of most white lab coats, few medical apps have been optimized for the new format.)

But apps for the pros are only part of the story. The medical app marketplace extends to sick patients—and the worried well. People suffering from asthma or diabetes can download applications to track their symptoms and treatments, with AsthmaMD and Islet, respectively. Hypochondriacs can keep tabs on disease outbreaks with the HealthMap app. Patients enrolled in speech therapy at the Hollins Communications Research Institute can get an app to help them stop stuttering. And those with prescriptions for medical marijuana can even pinpoint any nearby (legal) dispensaries with the Cannabis app.

Now, go download two apps and text your doctor (or patients) in the morning.