I have been using portable GPS systems for about 10 years, and have used them on commercial aircraft many times.

American Airlines now prohibits them, and says so in their in-flight magazine. Nevertheless, I have used my portable GPS many times on AA flights, and I have been told twice, quite sternly I might add, to turn it off. I do not know of any other airlines that prohibit GPS.

IMHO, airlines should WELCOME portable GPS units. They pose absolutely no danger to any on-board electronic systems, since they are receivers, not transmitters, and any EMF field they emit is incredibly tiny. If passengers had them on board on 9/11, they might have been able to figure out the upcoming events, and even prevented them, as the cell-phone using passengers were able to do on the flight that crashed in Pennsylvania.

Not only that, as other postings have said, they are just plain FUN on airplanes.

How can we convince AA to allow GPS on their flights?