Google Easter Eggs [Update: April Fools]
[Update]
Gmail Custom Time
gDay™ with MATE™
Google has some easter eggs for easter.
The Strangest Sites in Google Earth
The Most Spectacular Sights in Google Sky
Google egg-drop game
Gmail Paper - lol
http://www.google.com/mentalplex/
Search in Klingon/
Search in Elmer Fudd
Google Gulp