This chapter reports the authors’ use and refinement of a wireless audience response system (ARS) over a 10-year period. The motivation for this effort was to replace the traditional passive lecture with a more interactive classroom. Our classroom procedures and the evolution of these procedures are detailed. The authors also illustrate how ARS systems can be applied in a variety of ways, including the use of modified multiple-choice questions. ARS systems allow for both formative and summative assessment in real time, which is a unique and desirable property. The use of ARS systems similar to the ones described has increased rapidly in the past few years. A brief survey of current and proposed commercial wireless keypad systems is included.