Not exactly server equipment but let me try. So what can you do with old computers? Clean them!
Back in 2002 (as you can tell by my old-fashioned cell phone) I was working for a university library in Poland which had a set of PCs put in the main hall to access the book catalogue. These were good old HP Vectras with 386 CPU, running MS-DOS. While relatively pricey, they were extremely reliable, even in such harsh conditions.
One day we decided to open them up and see how much dust they accumulated. We were in shock to find a thick layer covering the whole MB and PSU. None of them died. So we gave them a good cleaning, just as a way to thank for their reliable service.
