The Nokia N900 is an "Internet Tablet" and a GSM smartphone. However, you'll have a really difficult time finding medical apps for this device since it does not run your "typical" smartphone operating system. You just won't find much medical software that will run on Linux Maemo. However, if you're content researching and accessing all your health content via a mobile web browser, then the N900 may end up working out for you.
I wouldn't recommend the N900 to medical students or residents because you'll be much more productive if you can load medical apps directly on your device to boost your productivity. If you're looking purely for a recreational device, then the N900 is a great little gadget "toy" for your bag or purse.