I agree that you might be better off without one, or you could just have one and not bring/use it in classes. That way, you have to focus on the professor and the lecture. Most courses will give you hints about the key stuff you need to know, and you will likely remember things better if you just listen hard, take notes, and draw out diagrams.
Laptops can help if you are the type of learner who prefers to type your notes or follow along in the PowerPoint, but they can also turn into a distraction pretty fast if you get bored. A fair amount of students with laptops tend to start IM-ing, surfing the net, or even playing videogames in lecture. Maybe they can multitask a lot better than I can, or maybe they're not getting as much out of lectures as they could be. If the professor's lecture is really that boring or unecessary, then why not skip it altogether and just focus completely on the other stuff?
As for the journal articles, research, and other stuff, you will need computer access for internet, PowerPoint, word processor, etc. You can use a laptop, desktop, or the library and computer lab machines. Those things all get done between or after classes anyways, but having a home machine is nice since you might want to work late on a paper or presentation after the library closes. I just have a 5+ year old desktop at home, I do my printing at the library, and I'd say that I get by fine...