Long ago I ripped out the guts of the little cage that held a loud 70mm fan to my 4600+ stock cooler. I twist-tied a 92mm fan to it, enjoying the cooling but not the noise, soi I dropped it and went for a Freezer 64 Pro.
Today, I went one step further. I had a 120mm fan... you can figure the rest.

The tinted area is approximately the top of the real sink.
It's not even quite as cool running as the 92 (which was 2800RPM, 56 CFM, versus 1200 RPM, 53 CFM for the entire fan, not just the part over the sink) but it's dead silent, a remarkable feat for a thin-fin cooler. (my old OCZ Gladiator would scream with any fan)
It brings back the silence memories of my first day with an A64 build-- icy 3200+
CPU, sufficient and quiet stock cooler,
mobo which did fan control (unlike a certain ASRock board) and quiet case with 120mm fan.
My concern is that I hot-glued the fan to the "cage" which snaps to the
CPU. It seems like hot glues soften at about 80C... while I hope to not see core temperatures much above 60-65C, should I be worried if the interior case temp, or the sink itself gets to 65C?
Long ago, I hung an 80CFM 120mm fan on my side panel with tape; it didn't stay and decided to give out in the middle of operation. I'm astonished it didn't grind up my (then valuable) Voodoo 3.