My iPad is my college companion. I use it to replace notebooks and take handwritten notes digitally instead now. This is super convenient for sharing with a classmate that missed class that day because I don't have to photocopy anything or exchange physical notebooks, I just email them a copy. And the size is perfect. I found a purse that it fits in so I carry it with me everywhere. The mini netbook thing I had tried to use before just couldn't compare.
I also have been finding textbooks to use on my iPad and since I'm a science major, the textbooks are usually very thick and very heavy. Being able to get them on my iPad reduces a great deal of that heartache and back pain (which includes financial pain, they're so expensive to use for just a few months, but e-versions usually cost less).
Additionally, I use the email sync, calendar, todo lists, internet, and facebook the most. I have a few little games on it but I don't want to get too distracted from my school work (facebook does that enough as it is). I also download awesome apps and tinker with them fairly regularly, sometimes stumbling on really useful things, other times I just learn something new and neat.
I imagine that I would use it for movies and music once I start traveling again. Perhaps even put a few more games on it for that. But for now, it's been a pretty awesome investment.