I can’t recommend Dropbox highly enough! I’m just about finished setting it up to synchronize my Mac to-do lists, Lightroom catalog, and other databases between my Macbook and Mac Mini.
How? It just takes a little terminal work if the programs can’t natively choose an alternate location for preference/database files. I’ll put a post on that in the future.
In the meantime, here is another referral link. If you sign up using it, you’ll receive 250megs extra, as will I. I’ve been using Dropbox ever since beta and completely overlooked that this existed.