Can I sync my Google calendar with my iPhone?
You can sync your Google calendar with your iPhone over the air. These steps require iPhone OS 3.0 firmware or newer. Before you proceed, backup your iPhone contacts and calendar by syncing with iTunes.
1. Go to "Settings" -> "Mail, Contacts, Calendars"
2. Touch "Add Account" -> "Microsoft Exchange"
3. In the "Email" field, type your full Google Account email address
3. Skip the "Domain" field
4. Type your full Google Account email address in the "Username" field
5. Type your Google Account password in the "Password" field
6. Touch "Next" and the iPhone will verify your username and password
7. Touch "Accept" if an "Unable to verify certificate" warning appears
8. Type "m.google.com" in the "Server" field that just appeared on the screen
9. Touch "Next"
10. Choose the Google services you want to sync to your iPhone (contacts and calendar are currently supported)
11. WARNING: Unless you want to delete all the existing contacts and calendars on your iPhone, touch "Keep on my iPhone" when prompted. This will also allow you to continue syncing with iTunes
Google Sync will begin automatically if you have push enabled on your iPhone. You can also open the calendar or contacts app and wait a few seconds to sync with Google.