Can anyone tell me if there is any difference between using the calDAv option for your google calendar vs. using exchange to sync your google calendar? Really, I am trying to see if I can find a way to respond to my calendar invites. The iPhone user guide says I should be able to do this using exchange or calDAV, but when I get an invite I don't see it in the invite section of my calendar - just the email notification that I receive an invite. Am I doing something wrong or does google not support that feature?