I remember the first time when I saw someone rolling one of those around on campus, and I thought, "wow, that's a great idea!" Obviously, I was in a building for graduates, because undergrads are still, to this day, too self-conscious to use it.
I started looking at the rolling bags at Target, and it's becoming obvious to me that I need it. There's a handle at the top of the bag, so you just lift it when you use stairs. I lug around too much crap: I need a WHOLE GALLON of water, a half liter of coffee, snacks, lunch (too broke to not bring all of said provisions with me), not to mention all the books! Many of these bags are cute, too, without looking imposing at all. I'm very glad that I know I won't strain my petit back anytime soon.