I pretty much print out everything that is under 15 pages. The rest I save to my desktop and read at my leisure (hahaha,,,, did I just say that??? I have no leisure).
I figure that my time is worth something and if I can read an article that is printed up and in my hand when I have a little break, I have made good use of the paper.
All in all, I had a little talk with myself and told myself to quit freaking out about paper and ink and just consider it part of the cost of my degree.