OsaSync

Using OsaSync, you can share and sync contacts, calendar, tasks and notes with other family members, colleagues or friends. Every change you make to shared items is automatically reflected on other computers on the network (or on 1 computer).
The program comes in two versions - Standard and Pro. The Standard version allows you to share items from contacts only, the Pro version also allows you to share other items. Both versions support Outlook 2000, 2002 and 2003.