Um, I think so. For an example, go here: http://www.fiberglassics.com/forms/forum818C
Notice a top general logo. (the one with the V in it)
Now, scroll down. YOu'll see three other logos used for various forums.
Going to any of these other forums would of course load up the sub forum for that but display the main site logo. Any way to change that to the sub forum image I used? Did that make sense?