An alternative bidirectional sync program that I've started using on Windows is called
Unison, as I mentioned in that other post. It's not as friendly as SyncToy, but I got used to it on Linux and am beginning to prefer it for batch jobs.
I've even managed to get it running in "active-active" mode between a Linux netbook client and a Windows XP "server", which was fun. In this mode the client actually launches it on the server and lets it check the target files locally. This saves time (local disk is faster than network) and traffic (by detecting and copying only the
parts of large files that have changed). This needs a bit of hands-on, though e.g. you need to install a SSH server on Windows, such as the
Cygwin one.