The MapFlows application I've been developing now has the option to generate quicktime movies of the heatmaps. These maps can either show or hide the background image of the level. For the purpose of analysis, I like to sometimes see the emergent structure of the level from the patterns of movement without having the map always in view. Below is an example of my "catwalk" map (using one of my experimental conditions) with and without the background map.

Without Background Map

With Background Map