"SSH key-based authentication is tried-and-true, but it lacks a true public key infrastructure for key certification, revocation, and expiration. #Monkeysphere is a framework that uses the OpenPGP web of trust for these PKI functions."
https://riseuplabs.org/en/projects
Sounds like a cool project, is the monkey still alive? The homepage linked on that page is dead, and the only code I could find doesn't look like it's been touched in a while.
This sounds pretty useful too:
"#BackupNinja allows you to coordinate system backup by dropping a few simple configuration files into /etc/backup.d/. Most programs you might use for making backups don't have their own configuration file format. BackupNinja provides a centralized way to configure and coordinate many different backup utilities."