Phospholipid vesicles exhibit a natural tendency to fuse and assemble into a continuous single bilayer membrane on silica and several other substrate materials. The resulting supported membrane maintains many of the physical and biological characteristics of free membranes, including lateral fluidity. Recent advances, building on the supported membrane configuration, have created a wealth of opportunities for the manipulation, control, and analysis of membranes and the reaction environments they provide. The work reviewed in this Account, which can be broadly characterized as the science and technology of membrane patterning, contains three basic components: lateral diffusion control (barriers), membrane deposition techniques (microarrays), and electric field-induced lateral reorganization. Collectively, these preparative and analytical patterned membrane techniques offer a broad experimental platform for the study and utilization of lipid membranes.