When you sync with itunes does it back up your calender and when you restore does it then restore it to the phone? Do you have to do anything extra to get it to do this or is it automatic?
it does and when you restore your phone to factory settings and connect it to itunes, itunes will ask if you'd like to set up the phone as new or restore from backup. if you choose to restore from backup, it will then put everything back onto your phone (except anything that was jailbreak related), including calendar...
but the better way to save your calendar events is to sync it to your outlook calendar and have that as a second backup in case your itunes backup fails