Pop Up Window

Is it possible to have a pop up window come up once someone logs in. Inside this window, it have a video of another person with a greeting, and other information? Has anyone ever done something like or similar? Other than ASP, what other technology is needed, FLASH?
Come someone show me an example of something like this? All help is greatly appreciated. The thought is to distribute these pop up windows (or better solution if someone knows of something better) to all our dealers across the nation. Each dealer will have its own personal inside sales rep and direct line for personal assistance.