So, no big surprise, I got mostly A's and B's. Primarily through whatever exams and book reports and other various assignments the teachers gave us. But some of them allowed for extra credit, and I tried to take advantage of that as often as I could to make up for that one test I didn't really study for or the homework assignment I turned in late or whatever.
(I had one English teacher who was a little too generous with extra credit. Most of my friends and I regularly finished the term with well over 100%. Often up in the 130% range! But she still graded on a 90/80/70/60 scale! As an experiment, I took one quarter and deliberately failed several quizzes and turned in blank homework assignments for several weeks. Then I tried to make up what I could with extra credit. The teacher was rather disappointed in me, as I recall, because I had only managed to get 113% that term. But I digress...)
My chemistry and physics teacher, Ms. Grener, had an interesting extra credit policy that I, being a devout comic fan even back then, really appreciated. She would give you one extra credit point for every comic strip you brought in that dealt with science. She only awarded the point for a comic to the first student who brought it to her, and I think there was a maximum number of points you could get in a quarter. But she had acquired enough comics over the years that, by the time I had her, her entire back wall was covered in comics. (Not surprisingly, The Far Side took a somewhat disproportionately high percentage of wall space.) I recall that, when I was taking her classes, I made a point to scan through the comics section of the newspapers (my folks got two) each morning at breakfast, ready to clip out anything resembling a science-related topic.
As I recall, she was pretty liberal with her policy on what constituted a "science-based" comic, and these two recent ones probably would've been acceptable...
... but I don't think there were many people who took her up on the extra credit offers while I was there either, so there was little danger of it getting out of hand.
This could easily be transferable to other areas, of course. A comic that references history or math or literature. It strikes me as an interesting way to keep kids eyes out for a subject matter.
The potential hazard now, of course, is that the Internet makes access to comics MUCH larger. Not only can we see the full range of comics offered up by the major syndicates, but all those hundreds of webcomics as well. I think you'd almost have to put a moratorium on certain titles that focus on only one subject. Like, you could never bring The Dreamer in for your American history class. But Ms. Grener had her caveats and limits on her version, so I don't think one or two additional ones would be all that difficult to include.
I just thought I'd throw the idea out there as a fun way any teachers out there might encourage some more engagement with the students outside of class. I know I had a lot of fun with that little extra credit scavenger hunt, and there's probably more than a few other geeks out there who would appreciate it too.