Speeding Ticket
You can change the gear and throw your speedometer off enough then have it calibrated, works sometimes if you get a easy going judge. Or you can request a massive amount of paperwork from the DA's office such as road conditions, weather for the day, last time the gun was calibrated, officers training on how to use the gun, etc. If they can't produce the info you can request that the case be dropped due to the fact that they couldn't provide you with enough info to properly present your case. I have done the first with good results but haven't been ticketed in a while and haven't tried the second one.
Good Luck!