Smith Micro has released ExecutiveSync for the Mac
(http://my.smithmicro.com/mac/executivesync/), an US$29.99 app
designed to let you keep your work and personal files up-to-date
between the home, office and on the road.

With the software you indicate two folders — whether on a laptop,
desktop, backup device or remote server — and hit synchronize.
ExecutiveSync goes to work comparing 35 different file aspects for
each file, updating changes and notifying you of conflicts.

You can synchronize files with long names or foreign accents. By
using more than just modification dates, you can synchronize files in
time zones around the world. ExecutiveSync uses a “time and state”
synchronization method to save detailed information about each file
and avoid errors. It works with Mac OS X 10.4.11 or higher.