Tokyo's University of Electro-Communications built Shiri, which literally means buttocks in Japanese. It difficult not to make wise cracks here so we will let them explain it:
"Shiri" is a buttocks humanoid robot that expresses various emotions with organic movement of the artificial muscles.
Example emotions such as "Tension", "Twitch" and "Protrusion" in attempt to express emotions on buttocks were added to SHIRI.
This project has two main points, one is the innovative use of robotics technology and its purpose. And second is to raise the argument as to what perceptions will be manifested in the minds of people who communicate with SHIRI.
Hmm. If you can make it through all 3 minutes and 51 seconds of the video, then you are surely one of those that agrees with New Zealand researchers Ian Yeoman and Michelle Mars that robot hookers will arrive by 2050.