In a distributed object-oriented system, it can be useful to find the location of a particular object. The distributed Object-Oriented programming language Emerald provides not only the ability to move objects between distributed nodes, but also a “locate X” statement that returns the location of the object X. Thus, if a manager object wishes to keep track of agent objects then it can merely “locate” them. However, this is a polling style that is inefficient. Instead, we propose a new language mechanism that tracks object moves and informs about each move to other objects tat have requested such info. We describe the background for the mechanism, the changes to the programming language and to the underlying Virtual Machine that keeps track of the objects.