http://www.google.com.tw/logos/midautumn09.gif

on google.tw google.cn google.com.hk

http://www.google.co.jp/logos/moonja09.gif

on google.co.jp

http://img0.gmodules.com/logos/krthanksgiving09.gif

on google.co.kr

More info:
http://en.wikipedia.org/wiki/Mid-Autumn_Festival

Korea: http://en.wikipedia.org/wiki/Chuseok

"The Mid-Autumn Festival, also known as the Moon Festival, Zhongqiu Festival, or in Chinese, Zhongqiujie, is a popular harvest festival celebrated by Chinese people and Vietnamese people (even though they celebrate it differently), dating back over 3,000 years to moon worship in China's Shang Dynasty."