Thanks Bill. So it is just me. :-) I've been messing with the Gather node but the results are inconsistent so far. The same Gather node settings used on various materials/objects ends up with some wildly different interactions. Incidentally (if you'll excuse the pun) I tried attaching an Ambient Occlusion node to the Ambient channel of a material and ended up with a surface that projected 'light' into the scene. Of course, it did so in a strange way and Poser fell over, but it does give the hint that someone who knows what they are doing could end up with something akin to an area light...