More granularity in placemark privacy settings

Something on the "that'd be nice to have" list would be per-placemark privacy settings. Rather than just have "always public", "always private", and "according to settings", there would be settings similar to the site-wide privacy settings. So on certain placemarks, I could put "Check-ins:Exact,Trusted; Posts:City,Trusted", etc. The downside is the added complexity in both the back-end and the interface. I'm not quite sure how I would implement this in a way that wouldn't confuse Brightkite newbies. An option would be to hide this (and other) features behind an "Advanced Mode" that is disabled by default on new accounts?