Using LR4 on 2 Computers

I use LR4 on my desktop and wonder if I can use it on a notebook and somehow "merge" the catalog on the desktop into the desktop catalog.

So then - I travel out of town, take the notebook computer and do work in LR4, when I return can I somehow merge the catalog with my desktop catalog?  I assume (always a problem I know) that the folder structure and file names on my laptop would have to be the same as my desktop in order for this to work, right?  In other words, I would have to have the same image files located in the same folders on both computers so that when I merge the 2 catalogs LR4 (on my desktop) can now locate the files in the same folders they were on whenI worked on them on my notebook - right?

Thanks for any assistance.  I'd really like to be able to import and tweak photos on my notebook while traveling, but ultimately they will reside in my desktop computer as that is the "master" LR4 catalog.  I eagerly await your knowledgeable replies,

Mike Freeze