After a long search I found this article:
http://www.google.com/support/calendar/ ... swer=99358
After much testing, I have it working
My Mac Pro and my MacBook are now nicely in sync!
If you follow the Sunbird instructions as well, you can see you can use other calendars, not just your main Google calendar one (for instance I have one for lectures, one for general uni, one for home, etc). Only thing I can add to it is that your other calendars need to be made private, and iCal doesn't see them until you restart the app.