http://office.microsoft.com/en-us/marketplace/EM102141191033.aspx
But, Outlook only lets you do this one at a time...one option is above.
Outlook® to vCard, vCalendar or iCal converter
Microsoft® Office Outlook® allows you to convert only one contact into a vCard formatted file at a time. With 4Team Corporations vSync add-on for Outlook®, you can convert any or all contacts to the vCard format. Convert all or selected Outlook® calendar events into the vCalendar, iCalendar, iCal format. Filter contacts and calendar events during import and export. Export contacts or calendar events into one file compatible with Lotus Notes, Google Calendar, iPod, and Mac.