I recently picked up a Macintosh Server G3 from eBay for less than $20. It came equipped with 64MB of RAM and a 233Mhz CPU. I quickly replaced the 64MB with 512MB and began working on overclocking the meager CPU. I tried 300Mhz, but it just wasn’t stable, so I stuck with 266Mhz, which has been rock solid under OS 9, OS X and Darwin. I installed a 20GB HD and installed Darwin 8.0.1 along with Mac OS 9.1. And the reason I picked the Mac Server G3 was because it has a real physical serial port which I can use to serial console to my server and use Open Firmware to boot into Darwin or Mac OS 9. My intention is to set it up as pure Darwin server running directory services for my Mac clients at home. I may have to wait for OpenDarwin 8.2.1 for that, however.