Some of my favorites:
"University of Virginia seeks Professor of English with specialty in “educational” technology for setting up MOOCs. Position will be responsible for attracting national attention with bombastic, unproven claims about the future of education; ideal candidate will be heavily read in David Brooks. Teaching load is ∞."
"The City College of New York seeks Assistant Prof to teach whatever is the current fad and then to go quietly when enrollment shifts. Interests should include all the classic literature as well as a firm grounding in current scholarly trends, combined with the flexibility to anticipate the whims of the administration."
"The Department of English at the University of Wisconsin-Madison seeks an energetic and visionary scholar of Victorian poetry. Tenure evaluations have recently been sped up thanks to our ability to subpoena your email and phone conversations. Promotion decisions have also been made swifter through the elimination of union agitators. The University of Wisconsin-Madison is an Equal Opportunity Employer."
I'm honestly not sure how funny these are to people outside academia, but they made me chuckle!