This bot would sense if people came near it and back away from the person.
i combined this idea with the emotions from the 3rd idea for my final project.
The waving robot
This robot would have a motion sensor and when a person was sensed the bot would light up and wave to convey that the bot was happy to see you.
Happy dispenser robot
This robot would have a button on it and when the button was pressed the robot would dispense whatever was in the storage container. It would then light up as if it was happy to help you.