Spanning Sync has released a new version (1.1.3) 
of its iCal-Google Calendar syncing utility, which offers several significant stability improvements.
In particular this release makes large syncing attempts more reliable and less memory-intensive.
Also, in Leopard it now allows the syncing of iCal-Address Book’s Birthday calendar, as well as CalDAV and subscribed calendars.
The developers are quick to point out, however, that Leopard users are still experiencing problems, ranging from data loss to minor annoyances. They offer a short and a lengthy explanation and some tips on how to unstick Leopard iCal when things go wrong.
Spanning Sync casts USD 25 for one year and USD 65 for a life-time licence, although a free trial copy is available from its web site .
It’s a horrible product for privacy-minded people.
They could have their program talk exclusively to Google’s servers to achieve the purpose, but for “some reason” they pass your data (including login details) through their own servers.
I don’t trust them and recommend you don’t either.
Quite so.
Mind you, I don’t trust Google’s servers either. Although I do instinctively trust Apple. Weird, isn’t it?
I host my calendars on icalx.com
Syncs with iCal without a problem.
no need for costly third party software..
(unless this thing does something I don’t know of)
USD 65 for a System Preferences plugin? The developer must be greedy!
I use SyncMate, it syncs Google and Mac for free. It is very handy and has nice interface. Why to pay for Spanning Sync if SyncMate does the same but for free?…
Moreover SyncMate syncs Mac with win mobile or nokia phones, PCs or Macs, PSP, USB drives, online storage. This is really all-in-one tool for mac OS X sync. And free version is available.
Check the info here http://www.sync-mac.com/syncmate-features.html