This is an old thread, but I'm reviving it.  I have been working on a render and it looked flat and pasted. I had to dig this thread out in order to review the AO.  It is definitely what the image needed.  I thought others might be interested in either a review, or if they haven't seen the thread before, learning something new to give more realism to their images.

Thanks again BB!

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi