you can only publish outlook 2007's online. if you use hotmail, you can use
the outlook connector and then share the hotmail calendar with other hotmail
users. otherwise, you need to use a 3rd party tool.
See http://www.slipstick.com/outlook/share_web.asp for some methods.
--
Diane Poremsky [MVP - Outlook]
EMO - a weekly newsletter about Outlook and Exchange:
(e-mail address removed)