Numerous solid-state properties depend on the crystal structure. Recently, the idea of searching for novel properties or novel functionalities at artificial interfaces – where a breaking of inversion symmetry and a change in the atomic environment occur – has been developing rapidly and has led to a large new field of research. In this short paper, we will summarize the properties of the 2-d electron gas found at the interface between the two band insulators LaAlO3 and SrTiO3, discuss briefly the recent observations of electron gases at oxide surfaces and examine the possible similarities and differences between these exciting systems.