I think that I am getting the hang of using Ambient Occlusion, but 1 question remains.

Many of the new "shaded" texture sets use the diffuse input Channel, my question is which blending or math node should I use to bring the AO node and the existing texture nodes into the diffuse input channel together, so that the existing node is not altered in function and the AO node works to it's fullest.

Hope someone can help

and thanks in advance
MARK