11. A system for annotating a stimulus comprising: an image capture device; and a computer coupled to the image capture device, wherein the computer executes an annotation generation module that interacts with the image capture device, and wherein the annotation generation module comprises logic for performing the steps of: detecting a plurality of facial expressions in an audience of the stimulus; interpreting the facial expressions to estimate a mood for a time period of the stimulus, wherein interpreting the facial expressions comprises: classifying each of the facial expressions as corresponding to an emotion from a set of emotions; and statistically analyzing the respective emotions corresponding to the plurality of facial expressions to estimate the mood; generating an annotation of the stimulus based on the mood estimated; repeating the measuring, interpreting, and generating steps to produce a plurality of the annotations that respectively correspond to different time periods of the stimulus; and indexing the annotations according to the respective moods, wherein the indexing provides a two-way linkage between the annotations and the time periods of the stimulus.
11. A system for annotating a stimulus comprising: an image capture device; and a computer coupled to the image capture device, wherein the computer executes an annotation generation module that interacts with the image capture device, and wherein the annotation generation module comprises logic for performing the steps of: detecting a plurality of facial expressions in an audience of the stimulus; interpreting the facial expressions to estimate a mood for a time period of the stimulus, wherein interpreting the facial expressions comprises: classifying each of the facial expressions as corresponding to an emotion from a set of emotions; and statistically analyzing the respective emotions corresponding to the plurality of facial expressions to estimate the mood; generating an annotation of the stimulus based on the mood estimated; repeating the measuring, interpreting, and generating steps to produce a plurality of the annotations that respectively correspond to different time periods of the stimulus; and indexing the annotations according to the respective moods, wherein the indexing provides a two-way linkage between the annotations and the time periods of the stimulus. 15. The system of claim 11 , wherein interpreting the facial expressions comprises: analyzing the plurality of facial expressions; and classifying a mood in real time from the plurality of facial expressions.