By giving intelligence into an artifact, there are a lot of chances for people to have more conveni.ent life. We developed a smart object, called Intelligent Gadget (IG), to give the intelligence into an object. IG consists of a hardware and software platform that can be attached to any kinds of the personal belongings. Personal objects that IG attached can be easily carried or possessed. With the reconfigurable and autonomous grouping characteristics of IG, we developed a personalized service that monitors the personal stuffs, called personal stuff monitoring (PSMon). PSMon prevents people from loosing their belongings and from not forgetting the personal stuffs which should.be carried. In this paper, we present the development of PSMon including its features, service environment, workmg scenario, and PSMon prototype.