Attentive User Interfaces are user interfaces that sense, display and reason about the user's attention for communication with them (Google TechTalk). One of the predominant ways of sensing attention is through knowing what the user looks at. For this purpose, we have developed a new kind of hi-res eye tracker, called an eye contact sensor, developed in collaboration with Xuuk, Inc. It senses looking behavior at over 10 meters distance. Current eyetrackers are very obtrusive. They require users to sit still or wear head-mounted optics, restricting their normal behaviour.