I have a GIGABYTE GA-X38-DS4 LGA 775 Intel X38 ATX Intel Motherboard. I also have a EVGA 8800GT 152MB video card.  I would like to add another.  I know my mother board is CrossFire compliant but I was wondering if that means that I can't go SLI.  Does anybody know.

No.  Your Mobo does not support SLI.

From what I hear, the official answer is no.
 
I have heard that there are people out there that write hacked drivers to make it work, but you'd have to check into that.