Non-communicable diseases (NCDs) are emerging as the predominant global health challenge of this century. Physical inactivity is one of the primary risk factors for NCDs. Therefore, increasing physical activity levels is a public health imperative. The arrival of affordable wearable technologies, such as wireless pedometers, provides one strategy for encouraging walking. However, the effectiveness of these technologies in promoting sustained behavior change has not been established. Insights from economics suggest that incentives may be a useful strategy for increasing maintenance and effectiveness of behavior change interventions, including physical activity interventions that rely on wearable technologies. The aim of this trial is to test the effectiveness of a common wireless pedometer with or without one of two types of incentives (cash or donations to charity) for reaching weekly physical activity goals. We present here the design and baseline characteristics of participants of this four arm randomized controlled trial. 800 full-time employees (desk-bound office workers) belonging to 15 different worksites (on average, 53 (sd: 37) employees at each worksite) were successfully randomized to one of four study arms. If shown to be effective, wearable technologies in concert with financial incentives may provide a scalable and affordable health promotion strategy for governments and employers seeking to increase the physical activity levels of their constituents.