Comedy is overrated. Everyone should be serious in their personal statements. Upbeat, but serious, as is appropriate for the profession of law.
I believe, in most cases, the PS is just a check against the student's writing skill and vocabulary, therefore, as long as you don't write "me want in Harvard now!!" you will be fine. I want my PS to stand out so that I don't get lost in the numbers, especially since my numbers will not be above the 75th percentile. I think a savvy cartoon might just be able accomplish that. I admit that I'm not the funniest of people, but that's where my cute and bunny-like girlfriend comes in .