I’ve been seeing this topic and have also been held back at the airport a few times to “answer questions”. I was recently directed to a video made available by the Muslim Advocates on their website (www.muslimadvocates.org) which give some advice on what you can do in that situation.
The video also provides info on what to do if they authorities come to your home for questioning. My feeling always is to have all the information that you could need and then make a decision on what to do when the time comes. Take a look at the video on their site and then come back and give us your opinion.