I recently spent three hours at municipal court. (I had to plead guilty to a moving violation.) Apparently the way these courts work is that they summon thirty or so people to arrive at 5 pm, and then we all sit around while cases are called. Some people were probably there for five hours.
The evening started like this: a few of us arrived early and sat down in the court room. Then a policeman came in and asked us all to go back into the hall and go through a metal detector. (I could probably have left anything in the courtroom under a chair while I did that.)
I wear my phone and PDA in a pouch on my belt. I removed that pouch and my keys, etc., before going through the detector. There was only one decent place to set my stuff down: on a table just beyond the detector, so I reached around and put my pouch and stuff there.
I walked though the detector without even a chirp, picked up my gear from the table and went back to the court room. I could have secreted anything in my pouch, even something solid weighing two pounds. The policeman did not even glance at it.