If writing isn't a feasible option - either because we're watching a video or I'm just too tired to deal with holding a pen...or I'm in church...then my brain wanders through shippy daydreams, picking one of my favorite fictional couples at the moment (current default: Jim/Pam) and spinning out a number of scenarios, ranging from fluffy to tragic to simple replayings of favorite canon scenes. That usually keeps me occupied as long as I need.
But before that, or if I didn't feel like thinking about TV, then I would write in my regular journal - probably 50% of the content in my 8 years worth of journals were written just before and/or during class (hence why I used spiral-bound notebooks). There was always ample ground to cover in there. The hellish theology class took place during my creative writing renaissance, so I was usually working on fanfic in there, but that's a rarer option.
Sometimes, I amused myself just by jotting down the time & my immediate thought whenever I looked at the clock, thus keeping up a running commentary of my thoughts like "killing me softly with his drone" and "if I grind my teeth any harder, they may break." Always fun to read later! Other times, I'd just start writing down a list/schedule of what I was going to do for the rest of the day. Doodling was a last resort, but when I had to focus 95% of my attention on taking boring notes, I'd draw random designs/shapes, or sometimes animals, in the margins.
This is why I never truly get bored. ;-)
P.S. Pay attention to these campaign posters. These are the only people left in the tournament that I actually like*. DON'T TAKE THEM AWAY FROM ME.
(* Well, there's also Barney, but odds are on him to win it all, and he's been creaming everybody, which is really boring. That said, I am so not okay with a world in which Jon Stewart outlasts Barney Stinson. And yes, I know House is still in it too, but he's up against Booth. Booth is hotly protective of his partner and has an adorable kid, while House wanders around stealing food from people and leering lecherously at Cuddy. There is no real choice here.)
P.P.S. Veronica Mars is the only woman left. Do you really, really, really want to choose Spike over female representation? That's right, I'm even willing to advocate quotas. This sort of crisis calls for it.