Temporal GIS is a topic that encompasses almost all studies. Last year I did a study on pesticide use in California. Unfortunately, the data was only available on a year to year basis, so in order for me to graphically show the drastic increase in pesticide-related injuries I had to use multiple maps. On each map, cases were visualized with a red dot. At the end of the project, I resorted to using three maps from three different years in order to show the growth of pesticides. This however, was somewhat taxing. I had to create and prepare three different sets of data to visualize. At the time I accepted this as the way temporal GIS could be dealt with, but now I ask the question if there are better ways to visualize, rather than overlaying or using side by side map comparison.
I wonder if a simple sliding time bar could be incorporated into arcMap (or something similar) as a toolbox. Existing objects would simply need an additional time attribute that the slider would select. As a user slides the bar, a different series of shapes and polygons would appear or disappear. This could also offer analysis tools. If the program is aware that two polygons are the same, but change in size and shape over time, it could possibly calculate this change.
I realize though, that this would be data intensive, especially when dealing with time scales that are very small. A year to year basis could be feasible, but on a smaller scale, such as second to second, dealing with hours of data could become unrealistic.
Google Earth has several features that allow the user to play sequences through time, but as PPGIS and HIC has proven, sometimes Google apps are not the best for data analysis.