Is there a way to have rigid bodies collide, but not transfer any force?

At least that's in essence what I need. I have a rigidbody platform that I need to move another rigidbody across, but as I try to move one across the other, the rigidbody platform starts moving due to the other object. I'm not sure if I should simply simulate my own gravity on the platform object and remove the rigidbody, or if there is some other preferred solution, since this method causes other problems.