Off-topic but closely related: In the Main Discussion Forum - National, TxBrandy recently launched Issue #1 of her e-zine, "Brandy's Bedroom."
http://www.eccie.net/showthread.php?t=67817
Inside it (it's in .pdf format) is an interesting and informative article, what to do if stopped and questioned by LE. The author, who himself had a run-in with Arizona LE, admits not being a lawyer, but ran it past a few who agreed with his items of advice.
Why I mention this resource -- knowing your rights is great, but LE will resort to ploys to get you to talk anyway -- you need to be prepared for them. This article mentions some of them.