I'm running 3 computers right now (2.533Ghz P4 Northwood) (2.8 Ghz P4 Northwood) and (AMD K6-2 (newest addition from someone who didn't want it anymore)) Might get another slightly old one tomorrow
Dell (2.533 Ghz P4)
1 x 92mm exhaust
self built (2.8Ghz Northwood)
1 x 120mm intake
2 x 120mm exhaust (exhaust + Seasonic PSU)
1 x 60mm CPU
K6-2 (Currently refrabricating since it had some dead parts)
1x 80mm exhaust (PSU)
1x 120mm CPU (50mm fan had died was the reason it wasn't working, so we've strapped a 120mm fan to it

)
when we are done with it it will have:
1 x 120mm intake
1 x 120mm exhaust
1 x 80mm PSU
1 x 50mm CPU (May omit this if I can find a slab of metal big enough to make a Socket 7 run passively with 120mm case fans. (It CANT be running that hot, the 40 CFM 120mm fan i have strapped to the current little heatsink makes it cold to the touch))