Formerlly only available in PRMan: Depth Map Based Ambient Occlusion Lighting
Now available in Blender (for the next release anyway, the following were made with pre-release code).
Faked GI (ala Vektor's tutorial)
The A.O. is definately darker but contains some additional detail. While I'm sure I could tweak the lighting rig I'm using for the F.G.I. to achieve similar results, now I don't have to.
And finally a (very much in need of tweaking the power and postion) key light added.
Ambient Occlusion with key
And if your interested in the particulars of the method please read this write-up
from Andrew Whitehurst (not related to me, blender, or the blender project)