What to do with your old PCs?

(Originally posted on my FaceBook profile)

Well I went from many useful places to not very useful ones, so I would like to make a short resume of a good techno Sunday. The question was: what to do with my old PCs?

1. My old Presario 700 came to life with Kubuntu http://www.kubuntu.org/. Runs fast after learning some basics. It will be loaded with educational games from http://gcompris.net/ and after a few small work will be owned by Marko and Andre.
2. I have some old desktop PCs that are working perfect. They might need a bit of RAM, cleanup and I will transform them in a NAS http://www.freenas.org/ or network attached storage. Useful for... backups. That free server includes an OS, and includes advanced capabilities as software raid. The backups will be for home and office.
3. Grid computing tool BOINC works for joining the processing power of many computers connected to a network. You can create or participate on a volunteer computing project like SETI@Home or http://boinc.berkeley.edu/projects.php You can help a lot by facilitating computing power for research.
4. For more powerful but unused computers... I think installing a Linux based Web server makes a lot of sense. I just neet to learn more about that.
   

I have in mind the idea for receiving old computers but in good shape, configure them and donate them to schools or kindergartens. I just need more people interested in helping me to realize it... we will see.