You can change the backround? I didn't know that.
You think you can use an animated backround? Like a video of sims acting like they are looking at you sim and giving reactions. (like take a video of sims praising and laughing, etc)
That would rule!)
I don't think you can replace it with video, since that would require using a .gif, and you must use a .bmp. That WOULD be really awesome, though.