In addition to the radio triggers, There were small optically slaved flash units on the market used 2 AA batteries & fit a shirt pocket. I'm thinking around $20. apiece, you would just set these around the room, usually behind stuff. lamps, plants etc pointing upwards. Just enough to brighten the background and not much else.
I think the GN was somewhere around "did you see a bright light"?
As the mom of an active 15 month old, I second the duct tape idea. I should have video'd my attempt to get a portrait of him on his first birthday (he's been walking since 10 months). In the end, I got a few semi-decent shots by handing him a distraction - foil wrapped roll of 120 film. I was using my Pentax AF400T (not a small flash) shooting through an umbrella to spread it out a bit. I had to tone it down to not blow things out (smallish area - 10x10ish), but the biggest problem was keeping him in the area covered by the flash and by the camera. It really didn't come down to how much light there was - just whether or not he was even in the frame and facing even sorta in the right direction to be lit nicely. The better shots were later when he was strapped to the high chair and had a cupcake for distraction.
I also have a SB-600 to use as a slave but it lacks the built-in optical sensor of the SB-800. Is it worth $85 to get the Nikon SU-4 or is there a reliable cheapy? There seem to be lots of negative reviews on Amazon for the cheapies.
You could buy these triggers http://www.amazon.com/Yongnuo-Wirele...6258713&sr=8-1
and attach the trigger to the rollei with this http://www.amazon.com/Kalt-PC-Hot-Sh...6258864&sr=8-5
There are several hot shoe slave on Amazon starting at around $8.