This is probably not a big deal for you experienced users but it was fun for me to figure out. I was playing with animating a small school of fish and boned the fish then created a seperate bone 'harness' and put all the fish in this. By adjusting the dynamics for the fish bones and for the 'harness' bones and then animated this bone layer and I can see that with a bit of work it would be useful to animate groups of objects like schools of fish, maybe some flying birds, a cluster of leaves blown from a tree. In case my tip isn't clear here is a screen shot and a mov file. Forgive the wobbly animation will work on it some more just trying to get it out before heading out for Thanksgiving dinner.