in flash you can now build projects that allow the user to respond in a more interactive way.
when flash 8 came out it aloud a designer to add video in their coding, this video can be a web cam that actionscipt detects motion movements and audio sounds.
here is a demo version of a flash project that uses motion tracking, the user here has to move to make the audio heard.
click here to see and here the audio in this web cam.
("oh yea you may need a web cam if your computer hasn't got one installed.") :)
to see more different types of web cam motions with audio and visual movments.