I’ve released the first alpha version of csync. csync is a client only bidirectional file synchronizer. You can use csync for different things. The intention is to provide Roaming Home Directories for Linux but you can use it to synchronize your music collection or create a backup of a directory. This is *not* intended for production environments and is designed for testing purposes only. This version is fully functional and you can sync two local directories or a local directory with a samba share.
More at http://www.csync.org/