This thread directly deals with that issue -
Question for the Attorneys/Cops
These others do as well:
Sage Advice/Never talk to the police :MERGED This one has a good overview of the rules of evidence which come into play when making statements to the police. (I know this because I posted it...)
Dont' talk to cops - even if you are innocent - this is a must see...
The simple answer: Card bad. Silence good. Lawyer good. Talk & no lawyer = bad.
But make your own choice. I no longer care.
I used to, but then I realized that actually practicing criminal law is no substitute for making a poorly informed choice based on reading things off the internet.
If you want actual information to help you make up your mind, try Getoffthex.com or totalprotectioninteractive.com and look in the legal sections of those boards. (Be warned, people may use foul language and be more blunt than you are used to here...but that's only because they care more about getting correct information out than someone's feelings.
)