Finally, the third category is social applications, where individuals share sensed informa tion among themselves. As an example, individuals can share their exercise data (e.g., how much time one exercises in a day) and compare their
exercise levels with the rest of the community. They can use this comparison to help improve their daily exercise routines. Example deployments include BikeNet [7] and DietSense [8]. In BikeNet, individuals measure location and bike
route quality (e.g., CO2 content on route, bumpiness of ride), and aggregate the data to obtain the “most” bikeable routes. In DietSense, individuals take pictures of what they eat and share it within a community to compare their eating
habits. A typical use case for this is for a community of diabetics to watch what other diabetics
eat and control their diet or provide suggestions
to others.