in osx snow leopard it was possible to get multiple google calendars in your ical without using the delegates functionality.
in osx lion its not possible (that I know of, and I have tried)
but in osx lion you might notice that you can only see your primary google calendar.
to fix this you will need to use delegates.
if you dont yet have a google calendar setup in ical yet, then its easy:
once you have your account setup then you will notice that it hasnt imported every calendar.
from a page thats well hidden in the google forums and is actually to do with iphones (i needed to do this step to get the delegates to show on my mac anyway…)
By default only your primary calendar will be synced to your device. You can sync additional calendars by visiting the following page from any web browser:
(Google Apps users can go to https://www.google.com/calendar/hosted/your_domain/iphoneselect, replacing ‘your_domain’ with your actual domain name.)
Select the calendars you’d like to sync, and click Save. The selected calendars will display on your device at the time of the next sync.
you need to visit that page from your mac, and click all the calendars you want to sync.
once you have selected the calendars you want, return to ical
you will now have all of your google calendars in your ical on osx lion!