OMG, sorry, I kept on editing the same file, let me revert to original... But shouldn't friction prevent rotation? I want it to rotate, but to stop quickly...
I'm going to try what you said and see what happens (and save it in another file, sorry, I reverted this to the original).
Edit:
What I'm really trying to do is make two balls (rotating normally) attract to each other, and once they're in contact, the bigger ball can take the other around. Like a planet carries things and not let them stay in the same point of space.