More and more, people are using low-power machines like the Raspberry Pi to build routers, automate their homes, and crunch for humanity through BOINC.
This is a simple collection of articles I've found that demonstrate methods of achieving the last example.
Running Collatz Conjecture alone:
http://boinc.thesonntags.com/collatz/forum_thread.php?id=1170
Many other BOINC projects:
https://burdeview.blogspot.lu/p/raspberry-pi-boinc-project-ive-created.html
How to build a Raspberry Pi cluster:
http://www.instructables.com/id/How-to-Make-a-Raspberry-Pi-SuperComputer/
How to use solar power to crunch for science:
https://www.rs-online.com/designspark/searching-for-aliens-with-a-raspberry-pi-and-the-sun
If anyone has any other articles of note regarding Raspberry Pi or similar computers, please post them in the comments!
And don't forget to earn $GRC for your endeavours! Click the .gif below for more information. <3