Just set up iTunes' Info pane so it synces with MobileMe, the iMac's calender and the calender that theiPone syncs with. You also must configure the iPhones' syncing so it syncs with a calender that the iPod also syncs with.
I have the set up in iTunes' so it syncs with MobileMe but today the data on the iPad is not correct. About half is missing. I've had it work correctly since I got the iPad in April. Data is correct on all but the iPad. Should I reset? What does that do to my data?