A service that uses OpenCVs cascade recognizer to see what it can find in submitted images.
For this to work, first you have to install OpenCV. That's not necessarily easy. On ubuntu 14.04 trusty, I used these instructions and it worked out: http://www.sysads.co.uk/2014/05/install-opencv-2-4-9-ubuntu-14-04-13-10/
Good luck with that.