Many, many years ago I was passenger on a trans continental flight before GPS receivers were common place. I had recently bought a portable GPS receiver. I asked the flight attendant if I could turn on the GPS in order to follow the flight (it was an FCC approved model). She said that she would have to ask "the guys up front". She came back with a big grin saying that sure I could use it, but the "guys up front" would like to take a look. So there I was with my new toy and an enthusiastic crew because they could now file direct rather than follow the zig zag VOR path. The batteries ran out before reaching destination but that was no problem since the crew just reverted back to normal navigation. Interestingly, it worked well in the cockpit environment - 737, but I guess the larger windows helped. Happy memories!