? We present a system for automatic monitoring and timely dissemination of multimedia information to a range of mobile information appliances based on each user's interest profile. Multimedia processing algorithms detect and isolate relevant video segments from over twenty television broadcast programs based on a collection of words and phrases specified by the user. Content repurposing techniques are then used to convert the information into a form that is suitable for delivery to the user's mobile devices. Alerts are sent using a number of application messaging and network access protocols including email, short message service (SMS), multimedia messaging service (MMS), voice, session initiation protocol (SIP), fax, and pager protocols. The system is evaluated with respect to performance and user experiences. The MediaAlert system provides an effective and low-cost solution for the timely generation of alerts containing personal, business, and security information.