Google Goggles is a visual search application. Take a photo, click a button and Google will analyze imagery and text in the photo for your search query. And that's Google Goggles for you. 1 billion images are included in the index today but Google says it has made the decision not to include facial recognition until privacy concerns are figured out. Want to know more? Watch this video.
Also, take a look at PC-MAG article on Google Goggles.