I didn't do it, officer, and I can prove it ... with math!
UC San Diego physicist Dmitri Kriokov fought his $400 traffic ticket (for runing a stop sign) and won, with this physics paper titled "The Proof of Innocence [pdf]," which he posted to arXiv:
After thinking Krioukov ran through a stop sign, a nearby police officer pulled him over and issued him a citation. According to Krioukov's paper, however, three physical phenomena combined at just the right time and misled the officer.
When Krioukov drove toward the stop sign the police officer was approximating Krioukov's angular velocity instead of his linear velocity. This happens when we try to estimate the speed of a passing object, and the effect is more pronounced for faster objects.
Trains, for instance, appear to be moving very slowly when they are far away, but they speed past when they finally reach us. Despite these two different observations at different distances, the train maintains a roughly constant velocity throughout its trip.
In Krioukov's case, the police cruiser was situated about 100 feet away from a perpendicular intersection with a stop sign. Consequently, a car approaching the intersection with constant linear velocity will rapidly increase in angular velocity from the police officer's perspective.
Physics - Is there anything it can't do? Link
But the officer did not show up for the court date, so the judge dismissed the case without me presenting my argument.
It was one of the most joyous experiences of my life, right up until the point I went to court and still had to pay the ticket. That was the day my faith in the justice system was obliterated. I still have all the drawings, equations, vehicle research, and picture (the entire file I took into court, 20 some-odd pages). I can't bring myself to throw all that work away, even after this long. Maybe I'll bring it out and show it to the kids when they get to that age. "See, THIS is when you are 'going to need this'... so get to the studies (and hope you find an honorable court room)"