I spend a lot of time worrying about my files, both at home and at work. I have a variety of machines in both locations, and it's a real challenge to make sure that I've got the latest version of all my files available to me wherever I travel. Over the years I've experimented with a number of solutions, from the Windows Briefcase to Visual SourceSafe to manual batch routines to Intellimirror, but none of them have really solved my requirement for bi-directional, multi-master replication.
SyncToy, released publicly in beta form in the last week, takes me a step closer than my current solution. It provides a bi-directional solution that incorporates file conflict resolution; it also handles many other more subtle challenges such as file renames. And it just happens to be another example of a .NET Framework-based smart client application!
You can get hold of SyncToy here; there's also a white paper available with screenshots, a description of how to use it and demonstration of how a scenario such as digital photography can benefit from such a tool. It's worth a try if you face the same synchronization challenge as I.