I was looking for a way to change my background images in a random order. I tried a few others, but had various issues, including control bars showing in Internet Explorer, etc. I was already using JUX Slideshow and liked that product as well as their personal support.
Basically it does what it says. It can show the background image in various ways, for example stretching it if necessary, etc etc.
My client likes it and works nicely.
After I installed it I made a suggestion regarding random image capability. Within a day or so they added that feature to the module.
I recommend JUX Background Slideshow.