Begin by melting down the chocolate in the top of a double boiler until smooth, stirring constantly. Set aside to cool for 5 minutes.
Combine all the ingredients in a blender or food processor and blend until smooth. Refrigerate until chilled to firm it up (about 40 minutes), then you can either serve as-is, or scoop the mousse into a frosting bag fitted with a large star tip and pipe the mousse into small serving bowls. Serve immediately.