I found a webcomic today called xkcd. (No, it doesn't stand for anything. The letters, I mean. Maybe the comic stands for something. I dunno.) The comic is about random humor, math, and general nerdity.
Anyway, I read through the archives. There are only 179 of them, and most are single-panel. Check it out! Keep in mind, however, the following disclaimer shown beneath every comic:
Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).
A sample of a few of my favorites: