Del.icio.us launched (beta) their "private saving" feature tonight. This allows you to bookmark an item with a new "do not share" flag to keep items from your public bookmarks.
This change is somewhat controversial as some folks don't want to see the social networking power of Delicious reduced by offering a means to make bookmarks private. The folks at Delicious are obviously aware of this, and will be monitoring the effects...as Joshua notes in the announcement, "we will be watching how this feature impacts the community".
I see it as an opportunity to increase the social network fabric by giving individuals another reason to use the tool, or use it more frequently. Many folks will use it to store bookmarks of important but not public information, which hopefully serves to increase the overall usage of Delicious in the process.
Filed publicly in: del.icio.us