Writing about web page http://www.xkcd.com/
Webcomics are generally the domain of the geek - the basic requirement for keeping up to date with them, that you're willing to check the internet regularly, although less of a barrier to entry since the proliferation of my.space and facebook, still suggests the edges of the realm - webcomics are an internet phenomena, and they belong to those who love the internet. Nowhere is this more true than with xkcd.
"xkcd" is a word with no phonetic pronunciation, and that about sets the tone of half of xkcd's humour. There are extremely geeky jokes here, and I don't mean "geeky" as in dungeons and dragons and lolcats (although that particular colour swatch of the geek spectrum is well represented). I mean geeky in the sense of obsessive about particularly obscure areas of learning - science, programming, mathematics. Check the bottom two questions on the "about this site" page for evidence -
One on sorting algorithms, the other on the writer's favourite astronomical entity.
xkcd does assume a certain level of knowledge for some jokes. For this one -
you've got to have read "House of Leave" by Mark Z. Danielewski to understand the entire thing (have I blubbed about House of Leaves yet? I haven't? Oh you're in for a treat...) The writing is generally good enough that even if you don't understand everything in a given strip, the latent charm and character will buoy you up through the nerd culture references and hard science. And sometimes there's something so funny you'll find yourself traling wikipedia for half an hour before you decide whether or not what's just been suggested is impossible, or merely vanishingly improbable -
Tie all that to incredibly simplistic art and a sense of pure fun and you've got an excellent comic.