Continuous models of two-dimensional space economies can be classified under the following headings: (1) models of spatially extended markets, (2) spatial interaction models, (3) models of spatial population dynamics, and 4) models of spatial business cycles and economic growth. Interaction and migration models involve the disciplines of geography and demography, whereas models of markets, cycles and growth are largely within the domain of economics. The specific concepts associated with continuous spatial modelling and its various applications are surveyed briefly herein. The main aim is to present a few unexpected results from such models. These relate to the usefulness of the spatial theories proposed by Weber, von Thunen, Christaller and Losch.