Popular Mechanics magazine has posted their "Top Ten Tips to Avoid Speeding Tickets." Of course, my favorite is #4:
Keep quiet. Diamond says to present your license and registration and insurance card, and that's it. "You don't have to answer [anything] else—you have to say you're asserting your right to stay silent, or 'Please speak to my lawyer.' Do it in a polite way, nice and respectful. Antagonists get the most tickets. There are no warnings for a**holes."
It's good reading and generally good advice. Enjoy.