After reading How to get perfect UV sphere Mercator projection? It seems that there is no perfect solution for getting rid of the stretch at the poles of UV spheres.
According to What is the difference between a UV Sphere and an Icosphere?, icospheres can be used for stretch-less UV mapping:
All faces have the same area, which may be useful for certain types of UV mapping containing non-organic textures. An example that comes to mind is an isocahedral die or billiard balls where stretch must be minimized near the point where the number is printed onto the ball.
Incidentally, a lowish-poly billiard ball is exactly what I'm attempting to create.
However, my attempts at neatly unwrapping an icosphere have mostly failed (smart UV unwrap works perfectly for using baked textures, however I was hoping for something more like the example in the 6th post of this thread, with a nice clean rectangular map).
How can an icosphere (I assumed the term "geosphere" in the thread was referring to a (geodesic) sphere made of triangles, like an icosphere) be cleanly unwrapped? Or if it's not possible, is there another way to do this which I'm missing?
I'm planning on using the resulting sphere in the BGE.