Global Positioning System receivers (GPSr) are an indispensible classroom bridge between maps and the physical world as students go back and forth between projections and Earth. When using a GPSr, the spatial-relations skills students employ can help improve conceptual thought in areas such as physics, chemistry, Earth science, biology, and math. This column describes some of the magical properties of GPSr and other examples of what is loosely termed GeoEverything.