Before, I was running a single slot PCI slot fan which was on its way out, a vf-700cu and four cheapo 80mm case fans. Now Im running a dual slot PCI slot fan, still the vf-700cu and I replaced two of the cheap case fans with two much faster fans. Its pretyt loud, I cant sleep with it going, but the air flow is pretty nice.
My 7900gt is OCed to 700/810, I havent tried to go higher, but I might now. Before it was idleing at about 55C and under load it would up get above 80C. Now, idle is 51C and under load 71C. I had two windows of rthdribl open; one full screen on my 19" and about a third of a screen on my 24". The noise kind of bothered me at first, but its worth it now
. CPU temp went way down too, under load it use to hit about 53C, now it hovers at 46C. Pretty good, but next stop, water cooling. 
My 7900gt is OCed to 700/810, I havent tried to go higher, but I might now. Before it was idleing at about 55C and under load it would up get above 80C. Now, idle is 51C and under load 71C. I had two windows of rthdribl open; one full screen on my 19" and about a third of a screen on my 24". The noise kind of bothered me at first, but its worth it now