Picasaweb - Private Album Option

Previously I had noted that Picasaweb only had 2 options for shared albums: listed and unlisted. Now there is a third option: "Sign-in required to view". The help page explains

Select the 'Sign-in required to view' option to set the highest level of privacy for your album -- you specify who has permission to view it, and visitors must sign in to their Google Account to verify their identity. Anyone not included on the album's 'Shared with' access list will be unable to view the album.

Finally! Private albums!