It is an interesting time for mapping and monitoring of land cover using remote sensing. There are exciting new kinds of maps derived from remote sensing at a variety of spatial scales. For example, there are a number of new kinds of maps of land cover becoming available globally. Following in the footsteps of the global land cover products derived from the 1992 1km AVHRR time series (the IGBP Discover Map (Loveland et al., 2000) and the University of Maryland Land Cover Map (Hansen et al., 2000)), two new products have been developed. One is the GLC2000 Land Cover Map (Bartalev et al., 2003) made using data from the SPOT4-VEGETATION sensor. Another is the MODIS land cover map, made using a time series of data from the MODIS sensor (Friedl et al., 2002). All of these maps are categorical in nature and include classes roughly at the level of biomes. There are differences between the legends of these maps, but their basic nature is similar. A somewhat different set of products are based on the idea of continuous fields, with a good example being percent forest cover (Hansen et al., 2002). These maps are also global and provide a different perspective on land cover.