I recently watched a video where Joe McNally used a Lastolite Skylite inside of a Irish pub to shoot a band. He used flashes shooting through umbrellas which were shooting through the Lastolite Skylite. I've seen him do this at Photoshop World in Boston about 2 years ago. The setup creates this huge soft light.
This gave me the inspiration to try this on one of my shoots. I used a strobe shooting through an umbrella which was shooting through a California Sunbounce 4x6' frame with a 3/4 diffusion panel. I also had a strobe with a beauty dish from the rear as an accent light.
Here's a shot of the lighting diagram...
...and here are some images I made with it.