A long-standing dream of artificial intelligence has been to put common-sense knowledge into computers�enabling machines to reason about everyday life. Some projects, such as Cyc, have begun to amass large collections of such knowledge. However, it is widely assumed that the use of common sense in interactive applications will remain impractical for years, until these collections can be considered sufficiently complete, and common-sense reasoning sufficiently robust. Recently we have had some success in applying common-sense knowledge in a number of intelligent interface agents, despite the admittedly spotty coverage and unreliable inference of today's common-sense knowledge systems.