_dodger, I don't know if you ever saw this, but I conducted a similar experiment in omnidirectional lighting earlier this year.

http://www.renderosity.com/messages.ez?Form.ShowMessage=680431#8

I needed omnis, or at least something close to omnidirectional, in order to simulate naked lightbulbs. I went a bit overboard with the spotlights (especially since I only had 128MB of memory), but basically the technique was the same.

I've since changed hosts, so here's a new link to the video:

Video clip (MPEG format, 1.37MB)

I hope that DAZ Studio and future versions of Poser will feature omnis, because interior lighting is a pain-in-the-tail without them.