This paper proposes a small, lightweight, and easily-relocated sensor terminal named "Portable" for acquiring a variety of environmental information. The Portable is equipped with a variety of sensors including a pyroelectric sensor, a proximity sensor, a sound pressure sensor, a thermometer, a hygrometer, a gas sensor, a flame sensor, and a laser range finder. We introduce three typical applications: abnormality detection, pedestrian tracking and automatic reconfiguration of several Portables for pedestrian tracking.