Seeing as to how so many of us here are college or high school students, there must be certain lectures more boring than others to warrant activities more productive than sleeping, such as --- that's right, gaming! So, what do you usually play during these yawn-inducing lessons, if you even do at all?
For me, I play Heroes of Might and Magic 2. Great game to waste away 2 hours of sheer monotony. Or, Space Rangers 2 is a great way to waste some time away too. For less boring lectures, I play Crayon Physics, something just to keep myself awake from time to time.
PS: I believe list also applies to those who are bored in their cubicles B)

Well I mostly played perv on the cute girls in the class

I don't. I like to learn.
Actually I play whatever is installed on my laptop that isn't too demanding (and doesn't cause the fan to scream, "HEY I'M PLAYING A GAME IN CLASS!") like AVP, Deus Ex, and of course the game that trumps all: Solitaire.

I usually just surf the web, as that allows me to tear my attention away from the computer in case the lecture suddenly becomes relevant.
I study computer science, and there are currently no girls in my classes :(

Yup. It's horrible.

I was in the exact same position, then I took a minor in screenwriting & creative writing. Then I thought "Damn, I picked the WRONG major!"

I think i need to take my laptop more often :P
I must be dumb enough not to think of this XD

Cave Story, Fallout (the installer is too old to get caught by the Windows admin settings on the laptop they lent me) and the four basic Windows games: Solitaire, Minesweeper, Pinball and the thing with the kings. Dunno if I'll keep doing that in the future.

Football Manager. Nuff said.

Pah I'm playing NHL Eastside Hockey Manager!

Kingdom of loathing..... if you don't know about it. go have a look. :D
An Adventurer is indeed me :P

Age of Empires 2

So THAT's why you went to Gnostic Mass

dopewars