asteroids

i have made space battle animations before but am thinking of making another, i am wondering if the action should take place in an asteroid field( or the rings of rocks around some planets). is there a way to quickly and easily create a realistic asteroid field( as in a random arrangement of large rocks with natural looking shapes) in blender. thanks.
my animations can be found here http://www.youtube.com/watch?v=wZ3PuVBRvs8 http://www.youtube.com/watch?v=wztlgUyrwK8 http://www.youtube.com/watch?v=uYS0vpOQEcs , the models used were created by me in sketchup ( who said sketchup was no good! ha ha)

If you download a blender from the buildbot, or if you use the stable Blender 2.65 release and grab the contrib addon bundle for it , in File -> User Preferences -> Addon , enable the “Testing” category and enable in the “Add Mesh” category the “Rock Generator”.

Then in Blender itself click on Add -> Mesh -> Rock Generator , you can press F6 (or look into the toolshelf operator panel) to change settings.
It allows to create rocks of many kind with a click or two, enabling you then to create asteroids that will look different from each other so you can have nice fields.