Depending on how much you're willing to spend, you could get a PDA. The cheapest Palm sells for around $100 and can run the ePocrates drug guide, the Merck Medicus (a textbook), and Harrison's (another text) for free. All you need is the initial investment. I'll agree with a previous poster about PIMP protector---it is far too basic for a 3rd year medical student.
If you do decide to get a PDA, start with amazon.com instead of palm.com. I was able to get my TX for significantly less than the manufacturer's retail price.