Also, how much of said "private data" is actually harvested the phone itself, other than perhaps location data?
Gmail: That goes to Goog's servers before your phone
Talk: Same thing
Contacts: Can be kept on just the phone without sync (for that matter, sync can be toggled on/off for most things)
Browsing history: Do they get anything if you use firefox instead of chrome, and/or don't sync bookmarks?
Maps/Latitude: Location stuff can be turned off
Most of the ways they can get information *from* the phone seem inherent in the functionality being used: i.e. use of gmail, maps, etc
It would be interesting to learn what data is being "sync'ed" beyond that needed to get the functionality out of the given apps.