"I'm trying to get iPhone to play nice with all my work calendars that sync over exchange. My personal calendar works great with adding/remove events. However, my department calendar which is in a public folder does not show up at all. Anyone know a work around?"
When last asked a year ago the answer to this question was that it wasn't possible. With the release of iOS4 is it now possible to sync iphone to public calendars/folders?
http://stackoverflow.com/questions/10082/iphone-exchange-calendars-in-public-folders