A challenge sphere to retangle

[Middy]

Here is what I want todo.

I create a sphere and apply a texture map of some sort. I also want to add points to the sphere. After that I want  to "unwrap" it to a retangle. Luckily the texture map is already in such a form but how to keep the coordinates.

I am not sure if this is a LWJGL question or a simple "go learn some geomitry problem. But I am preety sure people have been around this problem before, and I want to make sure BEFORE i start messing around.