Sometimes comedy doesn't have to be a grand performance; it just has to be light-hearted material you can relate to, that makes you smile.
We sure are roommates!
I have a job that I work at!
Other times, comedy can be abstract. It's not directly funny, but more of a planned absence of normality that is derailing enough to humor some people.
Fifteen bees
ostrich service
Comedy is a versatile tool that can easily repair the intolerable state of the day.
I've heard that with Ubuntu 10.04, making jokes about linux is now actually amusing.