1. A system for multicast distribution of presence information to a plurality of communication devices comprising: a plurality of communication devices, each communication device associated with a contact list that identifies at least one of the other communication devices; and a network capable of multicast communication with the plurality of communication devices, the network being effective to provide at least one multicast address based on the contact lists of the communication devices to the plurality of communication devices and convey multicast messages identified by the at least one multicast address to the plurality of communication devices, each multicast address identifying a group of multicast devices among the plurality of communication devices, the multicast messages including presence information about the group of multicast devices, wherein a portion of the plurality of communication devices receives the multicast messages identified by the at least one multicast address and extracts the presence information about the group of multicast devices from the multicast messages.