Here are two robot guys, Patrick Norton and David Calkins, discussing the reasons behind the competitions with biped humanoid robots (Source: Robots Dreams). It is a bit long but it is a good overview of the important issues. They also discuss proprioception which ties into the discussions about robots and embodied cognition.
Benjamin Wright
As robots become common in public, existing privacy laws will restrict the ability of the machines to make audio recordings of human conversations. Therefore, robot designers will make the machines record lots of other stuff about each machine’s encounter with humans. The records will no doubt include detection of chemicals and odors associated with individual humans. –Ben http://hack-igations.blogspot.com/2008/03/robots-as-keepers-of-legal-records.html