How can I sync my google calendar with my work exchange calendar with my iphone calendar?
The only way I've been able to do this (given that my employer will not allow my iPhone, etc. to connect to Exchange) is to have my primary calendar on my Google Calendar account be my work calendar, use the Google Calendar Sync application on my workstation at the office (always running) to sync from Outlook to Google (it supports only one calendar on Google's side, so whatever it chooses to sync with is your "primary" calendar and, thus, your work calendar), and sync my iPhone with my Google Calendars (see here).

It's not the most elegant solution, so I really hope someone posts something better that I can implement.  But so far it's working just fine syncing meetings from work to my phone (one way, I believe... never tried to schedule a meeting from the phone).