We are taking cousin's GPS (Magellan, which we used last year in Normandy with them), and although tsa.gov does not specifically mention GPSs, similar electronic devices are allowed, and I assume it's ok to carry it with us. I hate to put such an expensive, borrowed piece of equipment in checked luggage unless I have to. Does anyone know anything to the contrary?

We took ours on board with our carry-on. You just can't turn the thing on at 30,000 feet.

Of course, that was last May, before the recent threats. But, I suppose if you can take your laptop, you should be able to take your GPS.

That was my thinking, also; thank you!

Since a GPS does not trasnmit (like a cellphone), it should be OK. One of the limitations is that signal from external satellites may not be able to get into the plane (getting thru metal), plus most GPS units require 'line of sight' with three satellites in order to localise the unit, which may not be possible at that height.

Never had a problem taking my GPS either. I have a rather old "Garmin GPS 12", military grade, Arab version. Wasn't a problem with Delta eiter, after I switched it on at pre-boarding and explained what it was.

"GPS units require 'line of sight' with three satellites in order to localise the unit, which may not be possible at that height."

Um, actually the system is designed to work at great heights (it's for airborne as well as terrestrial positioning), so having more satellites visible over the horizon can only make your fix more accurate.