1. One or more computer-readable media comprising: a context service module executable to automatically receive context information from one or more context providers and process the information to determine a current device context for a computer device on which the one or more computer-readable media are embodied by determining, from the context information, at least one node associated with the context information and traversing at least a portion of a hierarchical tree structure of which said at least one node comprises a part, and wherein as the context of a computing device changes, the context service module processes the information to determine a new current device context, wherein the context service module is executable to receive at least one event registration from one or more applications that pertains to an event for which the application is to receive information pertaining to the current context of the computing device and to return information pertaining to the current context of the computing device to the one or more applications responsive to the occurrence of the event, wherein said context service module is configured to traverse multiple different, independent hierarchical tree structures, individual tree structures having different root nodes, and wherein at least one hierarchical tree structure is linked with and touch points into another of the hierarchical tree structures, and wherein said at least one hierarchical tree structure comprises multiple nodes in which individual ones of the multiple nodes represent physical or logical locations unique to an entity associated with one or more context providers, and said another of the hierarchical tree structures comprises multiple nodes individual ones of which represent standardized geographical divisions of the Earth.