Last year, Google Drive added an advanced image search feature powered by Goggles that recognizes objects and uses OCR technology to extract text. The same feature is now available in Google+: search for [sunflower], click “More”, restrict the results to “Photos” and select “Most recent”. You’ll find sunflower images from Google+ posts that don’t even include “sunflower”, not even in the image filename.
This also works for the images you’ve uploaded to Picasa Web Albums/Google+ Photos or the images uploaded by your circles.
{ via Android Police }