Sunny-
Aperture does not provide a good method to synch a Library between two computers. It is a serious limitation of Aperture and I suggest that while in Aperture you go to Aperture/Provide_Aperture_Feedback and request the ability "for a single user to synch a Library between two computers."
Note that reference above to "single-user" is important, because "multi-user" is a very different, much more expensive can of worms that most of us do not need or want.
There are many workarounds and all of them have issues of various kinds. The "sneakernet" drive Léonie describes is probably the best and certainly the safest, but do maintain very good backup protocol. Most important is to back up originals prior to import in to Aperture or any other images management application.
Aplle's failure to facilitate Library synch forced me to a different solution. Now I own just one Mac instead of two. I replaced 2006 MP + MBP with the strongest available 2011 MBP with SSD. The workflow goes where I go and and with Masters referenced and the Library on the SSD it is wicked fast and very convenient. I am replacing the optical drive with a 1 TB hard drive so Masters can live on the laptop longer (currently Masters are only kept on the laptop SSD until editing is complete).
OTOH if Apple provided supported single-user Library synch I would love to add the brute strength, desktop graphics and 4 internal drives of a Mac Pro back into the workflow.
HTH
-Allen
