BitTorrent Sync - Free P2P Encrypted File Sync
This looks like a great alternative to Dropbox. Since it is P2P, none of your files get stored in the cloud and there aren't any file size limits. :)
Website / Download (Windows / OS X / Linux) / Documentation / FAQ / How It Works
BitTorrent Inc. has opened up its Sync app to the public today. The new application is free of charge and allows people to securely sync folders to multiple devices using the BitTorrent protocol. Complete control over the storage location of the files and the absence of limits is what sets BitTorrentís solution apart from traditional cloud based synchronization services.
Dropbox, Google Drive, Microsoft Skydrive and Mega are just a few examples of the many file-storage and backup services that are available today.
All these services rely on external cloud based hosting to back up and store files. This means that you have to trust these companies with your personal and confidential files, and that your storage space is limited.
For those people who want to be in control of their own data there havenít been many alternatives, but BitTorrent Sync has the potential to trigger a small revolution on this front.
BitTorrent Syncís functionality is comparable to services such as Dropbox and Skydrive, except for the fact that thereís no cloud involved. Users sync the files between their own computers and no third-party has access to it.
Besides increased security, BitTorrent sync transfers also tend to go a lot faster than competing cloud services. Another advantage is that there are no storage or transfer limits, so users can sync as many files as they want, for free.
Earlier this year BitTorrent started a closed Alpha test with a limited number of users, and today Sync is being released to the public for the first time. (Source