How to keep two macs sync'd WITHOUT icloud


I'd like to keep two macs synchronized (i.e. identical re user files) without using icloud, or any other cloud based service. I.e. I want the synchronization to be strictly local.

Both systems (an imac and a macbook pro) are currently running OS X 10.7 but I will (eventually) upgrade them to Mountain Lion. Third party software is ok (although if there's something in OS X that will do this, that would be best).

Any suggestions?