GPS use is ok on United and British Airways, but not on several other airlines. http://joe.mehaffey.com/ is the main resource for GPS questions and has a list of which airlines allow GPS and which don't.

It can take a while for a GPS to sync up at an airplane window (due to poor satellite configuration, multipath, and doppler shift) but it usually works. It has to be right at the window (though the blind can be closed). I was having difficulty one time (in United FirstSuite, where the seat is a long way from the window) and an FA lent me an external amplified antenna--which significantly improves reception (who says you don't get great service from the FAs on United?). I bought an external antenna for myself after that, but seldom take it now, even though it offers the conveience of attaching directly to the window with suction cups, 'cos it's one more thing to carry.

I don't use GPS inflight so much now that map displays are common on the IFE.

Garmin are the most popular brand. I use a Garmin IIIplus, the Garmin Emap is another popular choice. A GPS receiver is the most complicated consumer device you will encounter--it takes months to learn to use all the functionality (waypoints, routes, tracklogs) to full advantage. It's also one of the most fun toys there is.

A good place to buy Garmin stuff (no connection, just a satisfied customer) is http://www.tvnav.com/navhome.html

[Edited to add TVNAV link]


[This message has been edited by someotherguy (edited 12-16-2000).]