A processor-based personal electronic device (such as a smartphone) is programmed to automatically respond to data sent by various sensors from which the user's activity may be inferred. A wireless communication link may be used by the device to obtain data from remote sensors which may be worn by the user. A personal “scorecard” may be generated from the raw data and from data concerning other users. Personal, raw characterization data may be computed into personal statistical data by averaging over time. Then, it may be sent (anonymously) to a server that receives such data from many (or all) users. The server may return personal statistical positioning to enable comparison of the user to other participants. In certain embodiments, the generation of a personal scorecard from the personal position in the group statistics may be performed in the user's device.