US Patent 7630478 Method and system for multimodal presence detection

A presence device operable in a first mode and a second mode is associated with a communication device. In the first mode, a user using the presence device is biometrically authenticated and a presence confirmation input is received from the communication device. In the second mode, a user-entered log-in input is received from the communication device. A central presence database is updated to indicate that the communication device is active for the user. A received message which is to be routed to the user is sent to the active device indicated by the central presence database.