Most of us only dream about a robot that will pick up pizza boxes and assemble furniture, but Andrew Ng, an assistant computer science professor at Stanford, is building one. Leader of the STair -- or Stanford Artificial Intelligence Robot -- project, Ng, 30, believes every home eventually will have one. There are four concrete challenges: to have the robot able to clean up after a dinner party, clear the table, load the dishwasher; be able to fetch items from around the office or home; to assemble an Ikea bookshelf; and to give a tour of this research lab. Within a decade we would like to develop the technology. A year ago I said 15 years.