As home to more than 50% of the human population, urban areas are of growing importance as sources of airborne and water-borne pollutants and sinks for increasing amounts of energy and natural resources. Remote sensing has considerable potential to improve our understanding of these areas, but is challenged by the high diversity of urban materials and their small spatial extent. New passive and active sensors have considerable potential to improve our understanding. In this talk, I discuss the use of advanced imaging spectrometry analysis to map urban materials (roofs, roads, vegetation type including species), the use of thermal data to quantify the relationship between green cover, material type and land surface temperature, and the use of LIDAR to improve classification and retrieve vegetation structural information including Leaf Area Index. Examples are from the Santa Barbara area, drawing upon my own work and that of my graduate students.