Okay, I admit that my PC is awfully fugly. A free case from 2000 courtesy of my public library, slightly modded to fit mATX parts from 2007. Meh.
But little things add up. When I first got the case, I Dremel'd out the steel around the rear fan perforations. The 80mm fan then had to blow through a 70mm hole. Almost a year later, I finally got around to making a proper 80mm hole. The result? Under full dual-core FAH load, my CPU temps dropped 3°C!

With a room ambient of 23°C/73°F, full load temps with a stock fan and cooler are now just 46°C!
I figured I'd post pics with the new digital camera I got for Christmas. Don't get too excited!
The stuff at the upper left is some home brewed exhaust deflectors. Instead of filling the room with hot air and noise, it now flows to the left behind the desk. Feel free to ignore the Digital badge on the front; that's for my own satisfaction. I know the cable management looks crappy, but it really works well. There's a big empty space under the optical drives and that front USB panel. And no, there's NOT enough room under that exhaust fan for another 80mm one! Temps went up when I had a fan blowing in at the lower right.
Specs:
CPU: AMD Athlon 64 X2 4200+ oc'd to 2.42GHz
MOBO: Biostar K8M800 Micro AM2
RAM: 2x1GB Kingston DDR2 667
HDD: 2x WD 160GB 1 SATA, 1 PATA, Seagate 320GB PATA (640GB total)
OPTICALS: 2x Pioneer DVR-115DBK DVD burners
PSU: Antec Basiq 500W
GPU: PNY GeForce FX5200 256MB AGP 8x
MONITOR: ViewSonic LCD VA721
SOUND: Diamond Xtreme 5.1 PCI
CASE: PC Core Ltd. midtower
OS: XP Home SP3
ROUTER: Linksys WRT54GS
Just thought I'd show this, like Gordon suggested. It isn't the latest and greatest, but it's mine.
