We are using Server 2003 & Outlook 2003 for about 40 people. 10 are outside our AD Domain. (I don't need to share with them)

I want to share contacts and Calendars. Everyone needs to draw off a single list of contacts (vendors) plus have their own peronal contact list

The recepionist needs to share 2 managers calendars.

What is best for these purposes. Should I go the Exchange server (not desired) or are there some programs out there for this specifically?
Is there any way to do this w/o additonal programs?