Regarding great circles and flight routes, a nice feature of Wolfram Alpha is that it will actually display the great-circle route as a straight line, so you ca

Regarding great circles and flight routes, a nice feature of Wolfram Alpha is that it will actually display the great-circle route as a straight line, so you can see where it goes: http://www.wolframalpha.com/input/?i=moscow+to+havana http://www.wolframalpha.com/input/?i=moscow+to+havana The projection is a polar projection about the origin, so great circles through Moscow are straight lines.