Robots and Humans and ...?

This spring, I'm taking Human-Robot Interaction, a course taught by Andrea Thomaz. It's only the second time this course has ever been given.

The course is structured (and graded) as a discussion seminar/project. Each class session, we're going to have a student panel discuss and debate two or three relevant papers. We're to write a one-page critique of each paper and hand that in at the end of each class. There will be a few other assignments tossed in as we go along.

The biggest portion of the grade in the class is a team project, where we have to come up with something clever, implement it, write about it, and present it. The sky's the limit, but since this is HRI, the requirements are that it must be on a robot, it must be involve human interaction with said robot, and we must evaluate it using human subjects.

Reading and writing about the papers is going to be straightforward (and, I'm thinking I'll get a good jump on things since *all* of the papers have already been posted). The project's so wide open at the moment that I'm much more concerned about it. What do you think I should create? A robot that scowls? An emotive Roomba? A punitive pillow?