Google today introduced a new version of Google Earth, which among other new enhancements, sports an easier way for you to explore historical imagery of a place.
Now when you zoom to a particular location on Google Earth, it will pop-up a clock icon in the status bar indicating the earliest year for which historical imagery is available for that location.
You can then move the slider in the timeline, using your mouse or with the help of arrow keys, to see how that place may have changed over time.
For instance, here are aerial images of the Whitehouse captured during 1949 and 1999.
The following video has details on how may access historical imagery in Google Earth.
