While I've seen this done with Exchange Server, you may not be willing to expend the time and money. Look over http://www.slipstick.com/addins/olpda.htm to get a start on your new project.
Bob
I schedule my husband's appointments for his service business on Outlook on a Win XP desktop. I then sync his schedule to the Dell handheld he carries with him each day. We're using Activesync.
We also have an iPaq 1910 available. I'm wondering if it would be possible--or wise--to use the iPaq to schedule appointments while I'm away from the office during the day, then sync that with the desktop, then sync that with the Dell...
I absolutely do not want to risk losing appointments with a 3-way sync, but if it can be done without risking information, I would like to do it. Can I safely set this type of sync up?
Thanks.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic