I am running my Raspberry Pi (with USB hard disk) for backup purposes. Most of the time, the Raspberry Pi is idle. I am aware that using the Pi more needs more energy - I am willing to "donate" the additional electricity costs.
Is there anything that the Raspberry Pi can do for the benefit of the public? I am thinking of something like BOINC, however due to the limited CPU power that wouldn't have a big impact. Something using the spare upload bandwidth would be better.
Ideally, maintaining that solution would require minimal work apart from the first setup.