Are there portable hard drives that synchronize Outlook email messages and files?
One possible solution might be using an external USB Hard Disk, however it would require a bit of Outlook configuration on your behalf. Outlook really doesn't have a "synchronization" other than perhaps using offline folders with an enterprise Exchange server. If you are looking to keep two different installations of Outook in step, you're probably best off performing an export/import of an Outlook .PST file to/from each occurrence using the portable external USB drive. You could also try setting up offline folders for both installations, defining the portable external USB drive as the location for your .OST file. I'm really not sure how well that would work as I've never tried that scenario.