My first post here. Good looking forum with lots of info.  
 
I've got the upgrade bug and am having a problem figuring out what video cards will work on this board.
 
Can you use an 8x card on a board that only supports 1x/2x/4x modes?
 
If so, are there advantages or is it just a waste of money?
 
Recommendations welcome.

Yes, because there are no 8x cards.  There are 8x/4x cards, and there are 8x/4x/2x cards.  Anything up to the 9800 Pro will work fine at 4x, anything faster than the 9800 Pro will start to loose a portion of its performance due to the slower slot.
 
They all work.

Thanks man.

No problem.  Happy hunting!