Smart Phone
I love my iPhone. Not only because it is cool, but because it really helps me navigate my crazy business school schedule. I can check my email, manage my calendar, and even sign up for interview slots while I'm on the go (or, er, in class ...). A few times, I was meeting a person I had never met, and I could easily look them up on Facebook to see what they looked like. If you are blackberry person, I recommend going for one that can get the real internet. It is truly life changing to have internet at your finger tips!
Wireless Headphones
If you are planning to live with a spouse or roommate, these will make your life a lot easier. We waited to long to get these, but once we did they were key! Now my husband can watch the game, while I still get a quiet apartment to work in.
Sennheiser RS120 926 MHz Wireless RF Headphones with Charging Cradle
Zip Fizz
Lack of sleep is par for the course in bschool. I found a great alternative to coffee called Zip Fizz. It's a powder combo of caffeine and vitamins that you mix with water. This stuff has a small but devoted following at Wharton. You can buy it cheaply at Amazon or Costco.
Zipfizz-Healthy Energy Drink Mix, 30 Tubes Variety Pack
Pandora
I have this on my iPhone, and it has been a lifesaver at times when I've been trying to finish a paper or study for an exam in a distracting spot. All I need is a good station to drown out the noise and I can focus.
www.Pandora.com