Hmm..since I'd have the time, I would try a number of things
1) Close your eyes, rub your temples, and pretend to be concentrating intensely for 95 minutes on PS, then wake up and bubble like crazy in the last 3 minutes.
2) As the proctor is taking up answer sheets, grip your paper so tightly they can't take it. Then, as they yank harder and rip the answer sheet, exclaim, "OMG you've ruined my life, what have you done??"
3) With 1 minute left in the writing section, shout, "OMG, WAS I SUPPOSED TO BE WRITING??"
4) With 1 minute left in BS, shout, "OMG THIS ISN'T THE GMAT!!"
5) Fall out of your chair in the middle of the test and pretend to be having a seizure, then as people rush to help you, get up and say, "Nah I'm okay, I was jus messing with ya."
6) Stare at the test next to you, and when they bubble in an answer, shake your head and say, "Oooh....you know wut? Yea...I really wouldn't pick that if I were you."
7) Strap a gigantic wall clock to your wrist, and try to pass it off as a watch.
8) When the proctor asks you to read the instructions on the back and look up when your done, stare at the instructions and NEVER look up. If they ask whether you're done or not, say, "no wait..hold on..still reading" See how long they will put up with this.
9) When the proctor asks if there are any questions before you begin, raise your hand and apologize to everyone beforehand about your explosive diarrhea.
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