US Patent 6941345 Real-time, text-based messaging between devices in plural communities

A communications system includes a plurality of communities each associated with a service provider. Text-based messaging sessions, such as chat sessions, may be established between users in the communities. A request is received from a user in a first community, the request indicating a desired text-based messaging session with a user in a second community. The user in the second community is notified of a request, and it is determined if the user has accepted the request to establish a text-based messaging session. If so, the text-based messaging session is established between users in the first and second communities. If the user is not available, predetermined information stored in a server may be accessed to determine a plurality of devices that may be employed for communicating with the user. A message is sent to at least a selected one of the plurality of devices.