Been using this for about a week. Pretty good if you really love Apple iCal but use gCal elsewhere.
Google Calendar CalDAV support
I’m not a big fan of Apple’s iCal, when compared to just using Google Calendar in the browser. Now, I’m sure there are plenty of shortcuts I don’t know, and I started with Google Calendar before I had iCal, which is a factor, but I just don’t like the interface or the functionality.
I’m spoiled by Google Calendar because it works very well, and works the same wherever I am, including on my Blackberry (and soon to be iPhone).
Anyhow, for those of you who loved iCal before you started in on Google Calendar, this is a pretty good syncing option for you – and it’s free.