I actually found interesting, implmenetation of LPV, based on Octree. It supports multiple bounces from muliple light sources, and it is bit faster than normal LPV technique.
Also LPV can be extended to support SubSurface lighting and glossy reflections. More over it support fully dynamic scenes. Overall while it have probably bit lower quality than Radiance Transfer techniques, it is more flexible in terms of what you can do with it.
And there is already implementation in place, all it needs is to be finished.
http://www.jiddo.net/index.php/projects/other-projects/80-thesis-octree-lpv