Google Calendar and Apple Sync Services
I’ve done a bit of digging around in both the Google Calendar Data API and Apple’s documentation on Sync services. And I see no reason why there’s not a Sync Services client for Google Calendar. The sync client just has a syncing tool (like the one for AddressBook) which launches anytime iCal syncs it’s Calendar data. The Google calendar client would join that sync session and sync with the Google API up to google’s servers.
Why am I not doing it (yet)? I have no clue about how to program in objective C, although a book is in the mail to me to attempt to learn. If anyone wants my help or insights into developing one, or testing one, I’m all up for helping out until I learn Objective C.
Update: I found an XML library provided by Apple that could possibly be used to create the XML entity to send to Google.
Possibly Related

I know nothing of objective C or Apple’s Sync Services, but this sounds like something useful. My ideas for using the Google Calendar Data API would be way less messy to implement if there were an easy way to synchronize between some data I have (for instance, a custom-generated schedule of amateur radio satellite passes in my area) and a Google calendar.