I have an OSX 10.6 laptop and an OSX 10.6 desktop on the same network.
I just want them to have the exact same files and applications at all times.
Any ideas of how to keep EVERYTHING in sync except the absolutely necessary system files?
maybe you want to reconsider what made you ask the question in the first place - I have a similar setup, but what I keep in sync is my ~/Documents folder, nothing else. I keep all my stuff there, and if an application insists to put things in ~/ I create symbolic links that point to ~/Documents.
Whenever I "leave" one machine, I trigger a sync from there to the other with rsync. I tried automation in the past, but in some cases it just makes things go automatically wrong. When I am on the road, I connect with OpenVPN to the home machine, and sync.
More elegant is keeping such a folder on the network, if the machines are all the time on the network, you could export it on one. That would not work for me, as each of the machines is traveling reagularly.