Maybe I just haven’t been paying attention, but when did Google start showing ‘Note This?’ links in search results for signed-in users?
I know Notebook launched in April 2006, but I can’t recall having seen this show up like this prior to now:

Is this another collaborative filter-Web 2.0-data collection manuever? Or is it just a ‘hey, no one knows this exists?’ moment? And why can’t I find people saying anything about this?
Need more coffee now.