Lorenzo points out two ways to keep Outlook synchronized without installing Exchange. Some of you may remember that I was looking to do just that last month.
The first one I tried was SynchPST. While the trial seemed to have worked, I wasn't very thrilled at the mechanics of it. Basically, it uses direct file operations on the PST file - which, of course, means that you can't have Outlook open.
That sucks.
OsaSynch - while I'm not terribly thrilled at their implementation - is better because it uses a separate file share to store the differences and synchronize it across the machines. The synchoronization process runs as an add-in, and monitors new entries etc.
So, instead of only running when Outlook is closed, it only runs when Outlook is open. Makes sense to me.
That said - I've noticed a few problems popping up lately - duplicate entries when you permanently delete something on one machine - and then a few days ago is just generally stopped synchronizing. I'm not sure if this is a function of the trial version or what - but there's been no indication that it is.
I would consider registering it, if I knew that this was because of an expired trial or something. But it's also not exactly cheap (79.95 for the 3-computer version, which also happen to be bound directly to a computer name - God forbid you ever change that name!) - and it still requires file sharing.
I'm still waiting for Ken's Outlook.Sync. If he doesn't have something soon, I might have to write my own.