As far as I have been able to determine, no. The closest you can get to this in Poser is using multiple spotlights. I once asked ockham about the possibility of a python script (for Pro Pack and P5 users) that would make any selected item in your scene behave as if it were a light source - much the same as the ball prop with a bunch of spot slights positioned around it so that it radiates light out in all directions, but without the need for manually loading and positioning all those spots. I think he did manage to come up with a script that does something very similar to this, if not exactly the same as I was thinking, which makes it easier to add these omni light sources to your scene. He is a really clever fellow and I am constantly amazed at what he keeps coming up with in the way of these python scripts.