Microsoft Outlook versus iCal versus Google Calendar
From http://www.google.com/support/forum/p/Calendar/thread?tid=044fe4493f88eba1&amp;hl=en&amp;start=80

peertimo
Level 1
1/4/11

"One confirmed hint: Spanning Sync works. First you have to set up Apple iCal with the same Exchange as Outlook. Then Spanning Sync can sync one way from that "shared"/same calendar and Google Calendar. Once it is there, you can sync it back down to your iPhone and iPad as a regular Google Exchange sync."