I have a Nikon D200. I used a point and shoot in residency but went to a full size dSLR once I got a job. The D200 allows for customization of settings and you can load your own presets. I have presets for OR, clinic, photoroom, etc. Yes it's clunky to carry around, but it takes great pictures. Which brings up another point....
It doesn't matter what kind of camera you have if you don't know jack about taking pictures. I HIGHLY recommend the Scott Kelby series on digital photography. It really made a difference in my photos and my understanding about the subject.
http://www.amazon.com/Digital-Photography-Book-Scott-Kelby/dp/032147404X
For taking pictures in plastic surgery, there have been a few papers published that have some good info. The best is probably this one in PRS form 2001:
Standardizing digital photography: it's not all in the eye of the beholder
Galdino, G M, Vogel, J E, Vander Kolk, C A
Another important issue raised by Max is the use of a macro setting. It allows you to take very close up IN FOCUS pictures and is nice for shooting the patient chart labels before you take a portrait photo of the subject.
--M