I looked at a few videos that talk about the ability to cull out moving objects using “Target Areas” in Unity 3 but I can’t find a very good explanation on how to do this.
I created a “Visible Area” with both the IsVisibleArea box and IsTargetArea box checked but when the moving object goes behind a very large object it doesn’t cull away like how the cars do in Unity’s video at 2:50:
http://blogs.unity3d.com/2010/09/22/unity-3-feature-video-occlusion-culling-with-umbra/
I tried to create a separate “Target Area” but it doesn’t cull out moving objects when occluded by other objects 
Any suggestions?
I didn’t realize that the target area must have a “High” or greater resolution. I was using “Low” and thought nothing of it but I couldn’t get an example to work with moving objects (only static). After changing the target area’s resolution, which by the way, didn’t necessary take a huge amount of time longer to bake (unlike changing the visible resolution!) my demo worked great.
It must not be high, it depends on the size of your dynamic object 
@deamora- originally I assume that and use the low setting… i’m using a primitive cube of 1x1x1 (1 meter/unit) and set the target area a size of 50 x 50 x 50 with a resolution of Low and I wasn’t able to get the moving object culled… if I change the resolution to High or greater than it works. I played around with the sizes of the target area and moving object without success until the resolution was increased. Perhaps they’ll release a step-by-step video like their iphone culling demo.