Methods and apparatus are disclosed for collecting presence information about a user from one or more presence sources associated with the user, such as applications, devices and locations. A presence agent is associated with each presence source; and the presence agents provide presence information to one or more presence servers. Typically, the presence agents execute on a processor associated with the corresponding presence source. The presence agent reports one or more of macropresence events and micropresence events. The presence agent optionally prompts the user to update the presence information based on one or more criteria, such as exceeding a time threshold since the last presence event. Continuous presence functions are generated for each presence source that characterize the likelihood of the user to be present on the corresponding presence source at a given time.