Just a few week back, wasn't Google rotating the whole browser page for a specific query?
http://www.gtricks.com/google-tricks/do-a-barrel-roll-google...
Google has tons of other easter eggs. Here is a Top 17: http://www.pcworld.com/article/142620/googles_top_17_easter_...
Apple's Siri contains easter eggs referencing "2001: A space odyssey", "HHGTTG" and other stuff: http://www.theverge.com/2011/10/12/2486618/siri-weird-iphone...
In MS Outlook 2010, the default picture for new contacts is a silhouette of Bill Gates from his "arrest mugshot".
Facebook has several: http://reface.me/hacks/facebook-easter-eggs/ http://www.yesbutnobutyes.com/archives/2009/05/facebook_east...
Adobe has included easter eggs, here are some for the CS5 suite: http://www.youtube.com/watch?v=lEmO9-RsVgQ