How to Sync Your iCal with Google Calendar (GCal)
It used to be one of the Holy Grails of Mac-dom: two-way syncing of your iCal with Google Calendar. Then there was Spanning Sync, but at $25/yr or $65/lifetime, it’s too pricey. Then there’s GCalDaemon—but with its complicated shell interface to a Java application, it’s not quite worth the effort.
Now there’s gSync. It installs quickly and pretty intuitively. (If it’s not intuitive—like it wasn’t for me—just go to the Help menu, and they have step-by-step instructions.) And it only costs E 10—about $20—for a license.
So far it doesn’t have the same problems I’ve had with previous experiences with Spanning Sync. And it doesn’t go through a intermediary server, like Spanning Sync. It just goes directly to Google. Just make sure to backup your iCals first—File, then Backup Database.