There's a warehouse in Sunnyvale where old computers go to retire. It's an impressive place, with stack and stacks of old equipment, some of which gets resold, some fixed up and donated to worthy causes, and the rest recycled. I went today to donate two old (but working!) 15" monitors, after failing entirely to give them away. From the size of today's pile of monitors, a dozen other people had the same idea.
I'll make another trip there next week after scrubbing an old P-II of any possible blackmail material. I was considering salvaging the case and a few parts and rebuilding, but after pricing out the replacement motherboards et al., it's less expensive to buy new, not that I need more hardware.