There's also a new "personal content" section in the settings, which lets you disable the integration with Google Contacts, Google Photos, disable location, location history and search history.
5 hours ago
Links that will continue to work
* Links to photos and albums whose URLs use your user ID number (and not your username).
* Links to Public Galleries whose URLs use your user ID number (and not your username).
Links that will stop working
* Slideshows embedded on websites.
* Picasa Web Albums & photos embedded on websites.
* Links to photos, albums, and Public Galleries whose URLs use your username (and not your user ID number).