A major challenge in conducting classroom experiments for larger classes is the complexity of assembling responses and reporting feedback to students. The author demonstrates how mobile phone text messaging can be used to overcome the limitations of pencil-and-paper experiments without incurring the costs of full computerization. Students submit responses as text messages, which are down-loaded into a spreadsheet for automated analysis and by return messaging. The author presents examples of experiments that have been conducted successfully using text messaging as the response medium. These can be run in any room from which the instructor can access the internet and are designed to economize on both class time and effort of the instructor. (Contains 7 figures and 22 notes.)