I have used it. But you need to have a window seat. I have a Garmin 3plus. It is interesting to go down in detail and see what you are flying over. I have not read about any problems using the device. I have not had it check going through the security check points. Given that my system is a bit old there is a lag between where the plane is and where the system thinks you are. Barry "Jerry Nelson" To: Sent by: cc: az-geocaching-admin@listserv.azgeocaching. Subject: [Az-Geocaching] In Flight GPS com Tuesday March 23, 2004 04:57 PM Please respond to listserv This topic comes up occasionally but I haven't seen it for awhile and for the first time I can use the advice. I'm flying to Iowa in about a week and wonder if I can use my GPS on the airline. Anyone done this lately? Jerry Offtrail (See attached file: C.htm)