This is a great start. What I really, really, really want is for this to return results from my private photos that I haven't shared yet!
Currently, I have lots of pictures that I've uploaded to Picasaweb (but I certainly don't want to share all of them), and I can only find them by stumbling through searching album names / dates....then I can find my images.
With Picasaweb going away, I hope that this functionality makes a return.
The mosaic referred to by +Thomas Hawk
should be just like the "Photo View" in Events: beautiful mosaic of photos from various contributors.