How to Sync secondary Google calendar on iPhone

Apple allows you sync with Google and Yahoo! calendar now. With iPhone OS 3.0, there're no more limitation of calendar synchronization, you can sync or subscribe to many calendars with CalDAV and ICS support. this is a benefit for those iPhone users who use Exchange or MobileMe for work, and use other calendars for personal. Let's see how to sync Google Calendar with CalDAV and subscribe to additional calendars via ICS files.

Step1
Tap Settings on the home screen to open the app.

Step2
Select Mail, Contacts, Calendars, and choose Add Account.

Step3
There're no built-in accounts we need, so select Other.

Step4
Select Add CalDAV Account ant the bottom

Step5
Fill in the following blank.
Server: www.google.com
Username: < This e-mail address is being protected from spambots. You need JavaScript enabled to view it >
Password: <yourpassword>
Description: <Calendar Description>
For Yahoo! tap "caldav.calendar.yahoo.com" in Server instead.

Step6
Now your have your calendar in iPhone.

Subscribed Calendar (ICS)
The process of Subscribed Calendars is much easier. Just email yourself to the ICS file
and click to open it. We all so have a guide for this process:

Step1
Click Calendar settings from down arrow next to the calendar you want to subscribe.

Step2
Then in the following page, you'll see Private Address and some buttons at the bottom of the page: XML, ICAL, and HTML to access these versions of a calendar. Now just click the ICAL button.

Step3
Copy the URL show in the modal dialog box and paste this to yourself in email. Or Download directly in an iCal support device.

You iPhone is finally possible to sync secondary calendars from Google : )