xkcd - A webcomic of romance, sarcasm, math, and language

A lot of the humor in this comic will be lost on anyone not steeped in computer and programming culture, but it's very good, proving once again that drawing talent has nothing to do with being a good cartoonist. Here's how the creator, Randall Munroe, explains its origins:

I was going through old math/sketching graph paper notebooks and didn't want to lose some of the work in them, so I started scanning pages. I took the more comic-y ones and put them up on a server I was testing out, and got a bunch of readers when BoingBoing linked to me. I started drawing more seriously, gained a lot more readers, started selling t-shirts on the site, and am currently shipping t-shirts and drawing this comic full-time.