Setting up Google Sync and viewing multiple calendars
http://www.idownloadblog.com/2010/07/28/how-to-sync-shared-google-calendars-with-your-iphone/
Basically, Google Sync is setting up your Google account as an Exchange account. Still have extra steps, however, if you want to see calendars other than your primary calendar. For example, my wife wants to see my calendar entries on her phone as she does online.
