Picasa lets you include photo feeds from public sites in your Google Photos screensaver. You can add and manage your screensaver feeds by following these steps:
- In Picasa, click the Tools menu.
- Select Configure Screensaver.
- On the Screensaver tab, click the Settings button.
- Select the 'Photos from public sites' checkbox.
- Click the Configure button.
- You can add new feeds, remove feeds, or select the feeds you'd like to use in the 'Public Photo Feeds' window that opens.