9Jun/100
Add a style to your Google Homepage
I found this fascinating quote today:
Now you can add and change the beautiful background images on Google.com, just like you enjoyed the amazing background images on bing.com.quickonlinetips.com, How to Add Background Image to Google.com, Jun 2010
You should read the whole article.
Update on this post:
Google had stop this feature, for reasons that Google had received a bunch of complaints about it. Users have thought that the background is not optional.