Create a map of the earth isn’t an easy problem. Projections basically tries to solve the problem of how to 3D element on a 2D surface.
Tons of papers have been written about this problem but a nice place to start is the wikipedia entry about Map Projections.
Some time ago I seen a awesome video from the project Unfolding the Earth: Myriahedral Projections. On it, the author divides the sphere into a myriahedron (a polyhedron with a very large number of faces) which allows to unfold the sphere in many different map projections.
Recently I could seen another nice experiment at the bl.ocks.org site. The Projection Transitions is an great map work example implemented with D3.js library which shows an animated transition of map projections.
Don’t you think D3 is becoming a great project? I think I need to get some time to spend on it.