http://boingboing.net/2008/07/28/law-prof-and-cop-agr.html
As well as the ACLU
http://www.aclu.org/drug-law-reform-immigrants-rights-racial...
And flex your rights http://www.flexyourrights.org/
In many states, police can ask you to identify yourself. Some states require you to answer this question.
Most states don't require you to provide identification, but some do. It's also a good way to disarm the situation, so many lawyers recommend providing your ID when an officer asks for it.
Beyond this, however, you should only have two things you say:
When the officer stops you:
"Officer, did I do something wrong?"
When the officer asks you any other question besides basic information (name, ID, etc):
"Officer, my lawyer has recommended that I do not answer questions like this. May I go?"
When your Miranda Rights are read:
Say nothing. Obey instructions.