Unity Tactical, designers of the ATOM concept, have opened up pre-ordering (with special pricing, free shipping, and free swag) of their ridiculously cool FUSION mounting system.
The FUSION is a modular mounting solution that allows you to use a single chassis to mount everything from sights, to lights, to lasers, and more in positions that allow all to work together in a way that makes sense. The heart of the system is the HUB which is designed to be mounted on the top rail of a railed hand guard and to which various different types of mounts and rails can be affixed.
It is really easier to show the pictures of the FUSION to give an idea of what it can do than it is to try write it all out here. Check out the FUSION on UnityTactical.com.