On vBulletin and Invision (I know, comparisons...) - I can run separate themes per forum. For example, lets say my forum is located at:
On this forum, I have forums.
Alright. You with me so far? Alright. Good. Now, let's say I want a special theme for the 'chit chat' forum. I can select that in the AdminCP. Now lets say I want a special theme for the 'Mac Oriented' forum that just screams Apple. Same with the PC forum. So I have the main forums theme, but I have modified themes for the forums themselves. You with me still or am I making absolutely no sense? What say you?