1. A method for ascertaining availability of a person having an associated address within a name space, comprising: (a) receiving a first agent report from a first context sensing agent, the first context sensing agent being in a first communication endpoint associated with a person and the first agent report comprising at least one first classification tag descriptive of a first event involving the first communication endpoint, wherein the at least one first classification tag is indicative of an availability of the person to be currently contactable at the first communication endpoint; (b) based on the at least one first classification tag, determining a probability value of the person being at least one of available and unavailable at the first communication endpoint; and (c) receiving a second agent report from a second context sensing agent in a second communication endpoint other than the first communication endpoint, the second agent report comprising at least one second classification tag descriptive of a second event involving the first communication endpoint and indicative of an availability of the person to be currently contactable at the first communication endpoint, the first and second events being different, wherein the first and second agent reports each comprises a unique identifier associated with at least one of the corresponding context sensing agent and corresponding communication endpoint, at least one address associated with the first communication endpoint, and at least one time stamp associated with a corresponding one of the first and second events.