I really hate how often I hear these "How many x's does it take to screw in a light bulb?" only to be disappointed by some cheesey pun.
I don't care that it takes two ninja to screw in a light bulb; I especially don't care that the trick is getting them inside.
Likewise, I certainly did not need to know that it takes one person from Treant to screw in a light bulb and two more to defend its sexual orientation. (Thank you, post-secondary educational competition, for that lovely and quite tasteful anecdote.)
I think these jokes have so much potential that's just wasted on lame attempts to mock groups of people. Am I the only one that realizes the immense power that we have?
Steve: Hey, Jim, how many E. Coli bacteria, such as those that brought about the Walkerton epidemic, does it take to screw in a light bulb?
Jim: Gee, Steve, that's a tough one.
Steve: The answer is that it doesn't matter because if they are allowed to fester and grow in our filth, infecting our resources, their numbers will astranomical. Given infinite resources, one E.Coli cell could replicate enough times in 24 hours to cover the Earth to a depth of 1 metre.
Jim: ...Oh, wow. That's really frightening. I guess I better take this lesson to heart and realize what a precious commodity clean water is. Thanks, Steve - you really opened my eyes.
See what I mean? We have a tool to raise awareness, and not just about lesbians.