There is actually a very in-depth tutorial on shadow mapping with the programmable pipeline, check out Tutorial 16: Shadow mapping
A quote on the site about Point lights:
Point lights
Same thing, but with depth cubemaps. A cubemap is a set of 6 textures, one on each side of >a cube; what’s more, it is not accessed with standard UV coordinates, but with a 3D vector >representing a direction.
The depth is stored for all directions in space, which make possible for shadows to be >cast all around the point light.