"School is a time to learn, exercise, and socialize, not to 'plug in'." - Quote my principal.
Well I guess your principal didn't go to University of Toronto! Many of our buildings have wireless Internet and people bring their laptops to class to "take notes" (aka go on Facebook and chat on MSN).
To stay on topic, here's my funny story: back when I was in my lower years of university, I would take Pink Tama to lecture with me and keep it on my desk while I took notes. (I use a traditional notebook and pen, but I'm in the minority for that.) One time I was auditing Intro to East Asian Studies with some friends, and the guy in the row ahead of me turned around and said, "You brought your Tamagotchi to class??" I nodded proudly. Then he said, kind of shamefacedly, "I left mine at home..."

But in my later years of university, the class sizes got too small to be discreet with my Tamagotchi. I don't care much if other students see, but I kind of do care if my professors see, because I might be asking them for reference letters later. I want them to think of me as a serious student. I don't want to take the chance of having them think that I'm frivolous!