I have an iPhone 3G running iOS 4.2.1 I want to copy (sync) all the events on my iPhone's calendar to my Google calendar. So far, all I have been able to do is sync the Google Calendar (which is presently empty) to the iPhone as a separate set of calendar entries.

I do not use iCal, so it is not possible to sync with that and export the entries to the Google Calendar.

Is my only option to manually copy all entries in my the default iPhone calendar to my Google Calendar, then sync back to the iPhone?