You’re about to yawn.
Here’s a section from Malcolm Gladwell’s book The Tipping Point about yawning:
Have you ever thought about yawning, for instance? Yawning is a surprisingly powerful act. Just because you read the word “yawning” in the previous two sentences – and the two additional “yawns” in this sentence – a good number of you will probably yawn within the next few minutes.
Even as I am writing this, I’ve yawned twice. If you’re reading this in a public place, and you’ve just yawned, chances are that a good proportion of everyone who saw you yawn is now yawning too, and a good proportion of the people watching the people who watched you yawn are now yawning as well, and on and on, in an ever-widening, yawning circle.
Yawning is incredibly contagious.
And just in case that wasn’t enough, here’s a whole bunch of yawning animals:

Yawning seagull’s my favorite. Okay. Time to stop. I’ve yawned three times already.
My roommate just asked me what I’m writing about. Guess who’s yawning next. 😉