Check out LA County’s app that allows you to explore changes over time comparing 2011 to 2014 high resolution LAR-IAC imagery. Just click and drag the time slider bar to see the changes of development and the effects of the drought.
SoCalGIS.org
Southern California Government GIS User Group – Working together locally in GIS
SoCalGIS.org 
Wouldn’t it be cool if they had older data as well? Heck, the older the better in this case for a fun comparison.