On my flight back to HK on SQ, the flight path map has been all the time mis-located in about 4-5 km difference. The below photo showed how the plane docked on the airport, not the flying position. I noticed quite several times the current GPS on various smartphones and tablets, esp. running on Android having this kind of GPS distance variance of around 3-4 km. Perhaps nowadays the electronic communication is much overloaded and jammed. As I consider this is the year of 2012, the technology shouldn't be like this.