I don't have much experience in this dept., but I get the feeling it would depend solely on who reads it. Will they appreciate an applicant with a sly sense of humor (plus in your favor) or are they hard-nosed professionally rigid types who give off no visible enjoyment at doing their job?

Since you'd probably want to work for boss type A, you may want to consider the blurb. But make it short and sweet, and don't overdo it like a Saturday Night Live skit which can take a neat idea and bash it into the ground.