Hi zanaque,

3 users on one computer with the same items?

Yes. How to share Outlook on one machine:
http://www.slipstick.com/outlook/olshare1.htm

If you have 3 computers you will need Exchange Server
http://www.slipstick.com/exs/index.htm

or without Exchange:

ZDNet UK recommend this tool:
http://reviews.zdnet.co.uk/software/internet/0,39024160,10004529,00.htm

On this site is an article on various ways to share Outlook data:
http://office.microsoft.com/en-us/assistance/HA011477571033.aspx

and a list of a list of third-party sharing tools is also on this site:
http://www.slipstick.com/outlook/share.htm

--
Oliver Vukovics
Share Outlook without Exchange: Public ShareFolder
Share your contacts, calendars or e-mails
http://www.publicshareware.com