I love the original Microsoft free power toy called SyncToy. It had its limitations, but as a free tool for syncing and comparing data between two sources, it was quite a gem. The latest version, v1.4 has been released and it looks like they have listened to our feedback with some obvious improvements. Go out and give it a try, you wont be sorry!
The ability to type in a UNC path; Support for longer folder pair names and ability to widen the left pane to see those longer names; The ability to support the maximum length for folder paths, and documentation was added to the help file about how to set up a share to be able to sync deep folder pairs; Better handling of the difference in precision between NTFS and FAT timestamps; More discoverable link to the help file for information on how to schedule SyncToy using the Windows XP Task Scheduler; Support for 800x600 screen resolution; Added a warning for users if the selected action will take some time to complete; Added brief explanations of the actions in the user interface; Improved behavior when choosing folders to include or exclude when there are large numbers of folders involved; Improved support for accessibility modes.