Despite what a crazed man at the party I went to last Saturday would have you believe, Terry Pratchett is a hilarious writer. For those uninformed, benighted among you who are unfamiliar with him, Pratchett writes comedic fantasy novels set in a world of his own invention: Discworld. I know that the phrase "comedic fantasy novels" has already lost half of my readership, which is a little sad because those departing are letting their literary snobbiness get in the way of enjoying some genuinely funny books, but more importantly because I'm only using Mr. Pratchett as a lead in to my broader discussion point.
Which is, footnotes are awesome. In particular, footnotes have an almost mystical ability to bestow humor upon whatever work they inhabit. Mr. Pratchett's oeuvre was my first introduction to this technique, which is fortuitous, since he is quite the master at it. There's something about taking a sudden, tangential departure from a text to focus on a minor digression that brings a smile to my face every time. Even bigger, "more literary" books use this technique: the most dramatic example I can think of is Infinite Jest, by David Foster Wallace. Said book has an entire section (20+ pages) written as a footnote, and features a lengthy comedic digression about the Mean Value Theorem (although he entirely botches the theorem).
I'm heartened to see that footnotes appear to have made the technological transition to the Internet. And so cleverly, too! I refer, of course, to Alt Text, which you may more readily refer to as "those little yellow boxes that pop up when I hover my mouse over the picture." And if you were to refer to them that way, I would not begrudge you, for I am no hyper-critical, pedantic overseer of tech terms.
But I digress. Point being, several web comics I read (Dinosaur Comics and XKCD being the most notable) use said alt-text in fulfillment of a similar role as footnotes; that being, tangential thoughts that contribute -- but don't directly relate -- to the humor of the piece in question. Viz, the alt text in this XKCD strip, which is hilarious if you happen to be a programmer and know what a goto statement is, and have read Cryptonomicon, and know who Goto Dengo is (which ties in to my second theory of humor, which is that every joke has the same humor value, which is distributed more-or-less evenly between all people who get the joke -- therefore, the less people who get a joke, the funnier it is to them).
And that's all I have to say about that. Trivial? Sure. Earth-shatteringly novel? Not a chance. All mine? Hell yes.