I'm using iCal on Lion to sync with my Google Calendars. I set up iCal to use Google's CalDAV server and it successfully syncs my primary calendar, but not my others. How can I get it to sync the other calendars I have as well?
Create a new google account for each calendar.
Or ask your favorite search engine and find the answer quite at the top of the list. For example, this one http://www.ehow.com/how_8251009_sync-multiple-google-calendars-ical.html.
It seems to be even much easier. Under Settings->Account enter the credentials to access the primary calendar on google. Then select the pane "Delegation". There you will find your other calendars, select "Show" and violà, they will appear in iCal (at least under Mountain Lion).
I found the only usable way was to use BusySync which allows you to use all of the calendars associated with your Google account in a sane manner.
Nothing I tried before this gave me access to anything other than my primary calendar.