My old PIII 1 Ghz is in an Antec Sonata case acting as a file and printer server for the home network. Passive heatsink on the CPU means the system is almost totally silent. After installing a PCI ide controller the capability is there to attach upto 8 hard drives which is handy for storing video recordings. I expect as SATA drives take over all my old IDE drives will end up in the Sonata case.
Using a KVM means no screen keyboard or mouse are required.