Although this was from 2007, I thought I would offer input. I work in higher ed with a lot of Mac users / junkies. The IPhone question came up almost immediately after Calendar was installed. Using the MS Outlook connector and iTunes for Windows; I was able to sync the iPhone to the Oracle Calendar. This was no big trick if you do the right things in the right order. This may not have been so one year ago; but with help and prayer, we now have a solution that is fairly painless.