I'm about to build a raspberry based robot for fun. It will have camera, microphone, distance sensor, wheels, etc.
I'm thinking about having features like face recognition with opencv so he will be able move around the house and greet family members for example :) Or receive basic commands via voice recognition.
When its battery is low, make it go outside and recharge itself with solar power. I think fairly accurate indoor navigation along a pre-recorded route is possible using a compass sensor and distance sensor.
