Some info for buyers, you need a 3g ipad to get the builtin GPS. I have both a ipad 1 and 2, and use it in a Learjet 45 at all altitudes up to FL470 behind a heated glass windshield and the gps locks on within a minutes and tracks perfectly, even with it sitting down on my leg . Its also being moved throughout the world and works great no matter if we are in the middle east or up in Japan. I wouldnt do the bluetooth gps, its just too much hassle... unless of course your plane has problems with the ipad getting access to the signals from the gps satellites.
A great mapping APP thats free is PD Maps.
It lets you download the google or many other map source maps before you fly via the wifi or 3g and stores them on the ipad and tracks you position using the stored maps enroute, very cool for pax or yourself .