iCalm is a small, wearable, wireless sensor platform for long-term sensing of physiological information along with low-cost connectivity to consumer devices. It has many possible applications, including customer-experience data gathering, health monitoring, and education for those seeking to learn about their own internal physiological changes during daily life.

Or just fun with babies and diapers:

No word on if it has smellyvision to give us odor readings along with skin changes.