Picnik is ending on 19 April 2012

The first list of Google application retirements for 2012 includs Picnik, a photo editing tool that was accessible via Picasa-web-albums (and perhaps from other places too) - it was an effective, though slow, way of adding a watermark to pictures.

I'm sure that PWA has a replacement tool for doing this ... don't have time to research what it is right now.