Dropbox.com allowed me to sync Outlook on my 2 computers, simply by dropping the pst file in a folder. Worked with Quicken, too. Magic. You just have to be careful not to have Outlook open on both computers at the same time.
When you install Dropbox, it adds a folder, My Dropbox, to your My Documents folder. Then, you just move your pst file to the Dropbox folder. When you restart Outlook, you will be prompted for the new location. After you’ve done that on one computer, add Dropbox to your 2nd computer. Wait a few minutes, and the pst file will appear. Then rename your pst file for the 2nd computer and start Outlook up. It will also ask for the location, and after you point it to My Dropbox, you’re in businees.
Dropbox takes care of syncing things automatically from that point on. I was dubious at first, but it works great.
Addendum
I kept getting extra PST files, named “conflicted.” After reading some more, I discovered that you have to let Dropbox download the latest PST file before you start up Outlook. Otherwise, Outlook may not pick up the latest version of the file, and when it’s in doubt, it writes an extra file, with the conflicted name embedded. Once I realized this, I now hover my cursor over the Dropbox icon until it tells me it’s through downloading. No more conflicted.