Google Sprite changes over time:

If you want to know more about CSS sprites and how to put them together, feast your eyes on Google’s:
Then:

Now:

Here’s the history of Google’s PNG sprite image

http://www.google.com/images/nav_logo.png

http://www.google.com/images/nav_logo2.png

http://www.google.com/images/nav_logo3.png

http://www.google.com/images/nav_logo4.png

http://www.google.com/images/nav_logo5.png

http://www.google.com/images/nav_logo6.png

http://www.google.com/images/nav_logo7.png

http://www.google.com/images/srpr/nav_logo8.png

http://www.google.com/images/srpr/nav_logo9.png

March 25, 2010 – http://www.google.com/images/srpr/nav_logo10.png

April 1, 2010 – http://www.google.com/images/srpr/nav_logo11.png

April 21, 2010 – http://www.google.com/images/srpr/nav_logo12.png

May 4, 2010 – http://www.google.com/images/srpr/nav_logo13.png

July 2, 2010 – http://www.google.com/images/srpr/nav_logo14.png (Added a magnifying glass)

July 16, 2010 – http://www.google.com/images/nav_logo15.png (Made logo bigger for Instant Search results layout)

November 8, 2010 – http://www.google.com/images/nav_logo26.png (Added the Instant Preview images)

November 15, 2010 – http://www.google.com/images/srpr/nav_logo27.png

November 15, 2010 – http://www.google.com/images/nav_logo28.png

November 16, 2010 – http://www.google.com/images/nav_logo29.png – seems to be color correction as well as logo size.

January 14, 2011 – http://www.google.com/images/nav_logo34.png

February 1, 2011 – http://www.google.com/images/nav_logo36.png – added star ratings and close x’s

February 14, 2011 – http://www.google.com/images/nav_logo38.png – added another star

March 24, 2011 – http://www.google.com/images/srpr/nav_logo39.png – added unhappy faces, hover state for happy face

March 24, 2011 – http://www.google.com/images/nav_logo40.png

April 09, 2011 – http://www.google.com/images/srpr/nav_logo41.png

April 12, 2011 – http://www.google.com/images/nav_logo65.png

May 05, 2011 – http://www.google.com/images/nav_logo70.png

May 09, 2011 – http://www.google.com/images/nav_logo72.png

July 15, 2011 – http://www.google.com/images/nav_logo79.png

July 20, 2011 – http://www.google.com/images/nav_logo82.png

July 29, 2011 – http://www.google.com/images/nav_logo83.png

September 14, 2011 – http://www.google.com/images/nav_logo85.png

September 14, 2011 – http://www.google.com/images/nav_logo86.png

September 20, 2011 – http://www.google.com/images/nav_logo89.png

October 9, 2011 – http://www.google.com/images/nav_logo91.png – Lightened some colors

October 28, 2011 – http://www.google.com/images/nav_logo95.png – Added a tick sprite and down-arrow

December 5, 2011 – http://www.google.com/images/nav_logo99.png

December 7, 2011 – http://www.google.com/images/nav_logo100.png

December 7, 2011 – http://www.google.com/images/nav_logo101.png – Added new window sprites

January 26, 2012 – http://www.google.com/images/nav_logo102.png – Changed arrows to carat-style instead of triangles; removed button borders, added “return” sprite. Reduced logo drop shadow & thickness, This is the first of the new “unified” look.

February 17, 2012 – http://www.google.com/images/nav_logo103.png – added G+1 red buttons

February 24, 2012 – http://www.google.com/images/nav_logo104.png – added info circle

March 03, 2012 – http://www.google.com/images/nav_logo105.png

March 16, 2012 – http://www.google.com/images/nav_logo107.png

May 02, 2012 – http://www.google.com/images/nav_logo110.png

May 10, 2012 – http://www.google.com/images/nav_logo111.png

June 11, 2012 – http://www.google.com/images/nav_logo113.png

June 25, 2012 – http://www.google.com/images/nav_logo114.png
You can’t get much more efficient than that…

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