With a bit more power this might make an autonomous floor scrubber. Maybe. OK, a lot more power. :)
The original bristlebot featured a tiny pager motor on top a toothbrush, and was powered by a coin cell. With a good power-to-weight ratio it could really zip along.
My scaled-up version was made from a hair clipper motor mounted on a scrubbing brush. I was doubtful that a rechargeable PP3 battery could provide enough power to get it moving, but it seemed worth a try. After 5 minutes with a soldering iron and a glue gun, my creation had taken shape.
The heavyweight bristlebot makes sedate progress down a piece of guttering. I think it's fair to say it's made for comfort rather than speed. :)