I've just posted an example of playing video and audio from a sketch, using Link buttons.

Link buttons are very flexible. In addition to taking you from page to page of a sketch, they can also link to web pages or activate files (including other sketches) on your computer. You can take advantage of this by putting an audio or video file alongside your sketch and using a link button to play the movie or sound file. Here's the zip file I posted containing an example and directions:


For Mac users, there's an extra feature: The sketch explains how to use AppleScript to make the audio file return control to Sketchpad immediately, and make the video file return control as soon as it finishes playing. (I'd love it if an expert in Windows scripting can provide similar scripts that work in Windows.)