you could always add another fan as a push pull system - one blows one sucks...
that is how my graphics card works... but unfortunately not my wife...
sorry the child in me couldn't resist.
Problem with any ventilated system is that no matter which way the fan works - air has to enter some how to enable it to be blown out again or in...
In the case of PS2's it means that the front grill gets filled with dust - the mess on the carpet I have made in one day by cleaning just three stations I was working on was amazing - note - white carpet is not a good thing to have on the floor in your work area....
If you can get a better filter element at the front like in some airconditioners that blocks more dust particales but still does not restrict air flow then that would be the best option - although cleaning would be needed all the time...
add to it that electronics statically attracts dust anyway...
Personally back to the Vertical horizontal thing - Vertical is better to prevent scratches from larger dust particles sitting in the tray - but I would say worse for cheap disks that are not balanced well...
My main arguement against placing vertical is that the laser lens assembly is designed for horizontal use... so it has to be better... doesn't it...?
