One of these articles may help you.
This from the first URL:
"Outlook doesn't have identities, but it does have "profiles" in Outlook 97, Outlook 2002, and Outlook 98/2000 in Corporate/Workgroup mode. In Internet Mail Only mode, each person willneed to log on with a separate Windows user profile. See Create Separate Outlook 2000 Accounts for details on how to set that up. In either situation, it is possible to keep mail accounts separate, but share other information."
www.slipstick.com/outlook/olshare1.htm
www.slipstick.com/outlook/share.htm
www.slipstick.com/outlook/sync.htm
www.slipstick.com/addins/calendar.htm