A search engine for figures 

 I got an email a few days ago urging me to try  www.zanran.com , a search engine "for finding data and statistics".  I'm skeptical of some of these search engines (I can never find anything I want on  www.rseek.org  for example), but I was pleasantly surprised.  I typed in "fatwa" and, lo and behold, uncovered a few papers that are of some relevance to the project I'm doing on Islamic fatwas.   

 My first reaction is that this is really a search engine for finding figures and tables, not necessarily "data" or "statistics".  But it turns out that I really like finding new papers by searching their figures.  It's much easier to tell if a paper is going to be relevant to my research by looking at figure 4 than by looking at the title. 


 Searching through papers by figures has had me thinking about the search engine I'd really like to see: one that searches for images.  It'll work like this: you take a picture, upload the picture to the search engine and then it uses image similarity algorithms to generate search results ranked by the similarity of the image.  This would alleviate the somewhat rare but annoying situation where you have a picture of something but don't know what it is.  There's really no way to google that... "Who was that random guy in our group photo?" 

 "Hold on, I'm googling 'guy with brown hair'..."