Sounds fun! I have a cheap handheld Lowrance GPSr that allows me to put in destination coordinates, then it will give info like time to destination. Some other features that would be fun to watch, speed, altitude, path plot, distance from home, ... This would be nice for the domestic flights where they generally do not display this information on the monitors. You could also plug in other coords to help identify objects on a clear sunny day that you know you'll be passing over, like certain Mtns, lakes, rivers, etc... Plus if you see something wierd from the plane and don't know what it is, you could record the coords and do some internet research later to find out what it was (use Google Earth).