I have a really old computer, like 1GHz T-Bird, 512MB SDRAM, 128MB Radeon 9000 Pro.
Check this out
It used to have a 850MHz Athlon in it, when I removed it I took the CPU fan from it and drilled a hole in my case about the same size. I took the fan and screwed it to the side, it works also.
[size=0.5]Full Aluminium ThermalTake Case
AMD Athlon XP 3200+ *400 FSB* Barton (2.2GHz)
ThermalTake Volcano 11+ Xaser Edition Air Cooling
1024MB Corsair TwinX XMS 3200 (Dual Channel 2x512) 2-3-2-6
256Mb XFX 7800 GS EXTREME
2x WD Raptors (10krpm 8MB Cache) 36.7GB using RAID -0
Video Logic SonicXplosion 5.1 Soundcard[/size]