Outlook 2007 - Easiest and most inexpensive way to share a calendar between 5-10 people?

Outlook 2007 - Easiest and most inexpensive way to share a calendar between 5-10 people?

What's the easiest way to share a calendar in outlook 2007 between 5-10 people on a local network? I have tried sharepoint and the password prompts are too much of a pain. Security is not an issue; ease and functionality are the priorities.