Read with great interest Joe's posting:
Is it Safe to use a handheld GPS Receiver on a Commercial Aircraft?
A definitive look at the question including the Government Rules and Regulations on the Subject
... however, at the bottom the faa link to the posted url has been moved ... can I get an update?
And then if you want to know what the FAA has to say about the use of GPS and other navigation
equipment for "real" navigation on aircraft, see: http://www.faa.gov/airports_airtraffic/ ... tml#1-1-19