Researchers at MIT are working on the development of a robot dog that watches what you eat and how much you exercise, and that motivates you to stay on track with your heath program. The robot is a modified Sony Aibo dog that monitors your pedometer and food diary wirelessly, so it knows if you're walking enough and eating right. The system is being designed by Cynthia Breazeal and Cory Kidd at the MIT Media Lab, who have also written a brief paper on the idea. When you ask the robot, "how am I doing," it responds by acting happy, sad or somewhere in between based on, well, how well you're doing with your weight management program. If you have met your exercise and nutritional goals, the robot will wag his tail, play music and jump up and down. The concept will be rolled out September 11 at the UbiComp conference on 11 September in Tokyo, Japan, and will begin a study on 30 overweight Boston residents in the spring.