Want to keep your files in sync but not have them stored on somebody else's server? If you have a Raspberry Pi, you can create your own Dropbox-like solution using the free BitTorrent Sync utility.
BitTorrent Sync runs on Windows, OS X, Linux and Android. It automatically syncs an unlimited number of files across your devices -- bypassing the insecure and sometimes unreliable cloud.
After losing his notes files stored on the diigo cloud service, Jack Minardi came up with this solution. The Raspberry Pi serves as the central server and the other devices connect to it for file updates whenever they connect to the network. Check out the full instructions on Jack's blog, including a script to start btsync whenever the Raspberry Pi starts up.
Replace Dropbox with BitTorrent Sync and a Raspberry Pi [jack.minardi.org via The Official BitTorrent Blog]
Photo by ayaita.