A helpful tip on this subject...
Recently bought a O2 XDA Orbit pocket PC/mobile with onboard GPS. Downloaded Pocket FMS to see if it would be useful as a backup GPS for GA flying. Didn't get round to trying it in PA-28 but found myself as passenger in A319 from Heathrow and thought it would be interesting to see how the moving map worked.
Switched it to flight mode and launched FMS. All well as we taxiied out to the runway. Watched the speed indicator build up as the take-off run started. Suddenly RING RING RING RING RING at max volume and PULL UP OBSTACLE AHEAD flashing in big red letters on the screen. Looks varying from filthy to terrified from surrounding pax. Not a good moment
. Just thought you might like to know.