OSX comes with a very powerful synchronisation server that powers the iSync processes. Apple lock this down and force users to pay a .Mac subscription in order to get Mac to Mac sync functionality. MySync from Mild Mannered Industries looks like it will be able to unlock the power of the sync engine for non .Mac subscribers. At the moment the software is in Beta and free to test (though there are still some bugs). I would like to see it integrate into iSync a little more.
David Harrison's musings on collaboration and I.T.