Gizmodo pointed out that the American Cancer Society has released a PDA application suite called C-Tools 2.0. C-Tools provides reference materials and recent news about cancer in a PDA-delivered format that's compatible with PalmOS and Windows Mobile operating systems.
Many Operation Gadget readers know that my wife Kathleen is a pediatric resident at Robert Wood Johnson University Hospital in New Brunswick, NJ. She uses a PDA at work all the time, as do most doctors who are recent graduates of medical school. A number of high-quality reference applications already exist in PDA form, so this is an established software category.
The C-Tools application is free to medical personnel. If it's well done and doesn't take up too much memory, lots of doctors will load it on their PDAs. I'm not sure about the extent to which other medical practitioners (physician's assistants, nurses, and nurse practioners) have adopted PDAs, so I can't predict how widely they will use this application.