Title: Measuring the universe with cosmic shear

Abstract: Gravitational lensing provides an unbiased tool to measure the distribution of dark matter in the universe. I will describe the tool, and outline past, current and future surveys. This approach is already providing the most robust, and amongst the most accurate constraints on \Omega, and the accuracy is improving steadily. The current CFHT legacy survey is intended to improve accuracies to the percent level, and future surveys can provide precision far beyond that.