With PowerPoint's Broadcast feature, you can present a slide show over an intranet to a designated group of people in real time and include live audio or video. (For audiences of 15 people or more, you'll need to use a NetShow server on a local area network.) The participants (except for the presenter) don't need PowerPoint—they just need a Web browser and access to the network server where you stored the presentation.
To schedule a broadcast: