My cousin is an ER doctor and relies on his Apple iPhone heavily for work and personal use. There are some excellent apps out there designed specifically for the Apple iPhone. Also consider Windows Mobile phones (depending on which carrier you use) as there are many applications available as well. To get an idea about specific applications per format go to itunes.com or Handango.com for Windows mobile applications.
What would be some phones recommended for someone that's a doctor, nurse, etc.? I'm thinking something along the lines of a smart phone, doesn't matter which carrier.