On June 8th, 2011 -- World IPv6 Day (http://worldipv6day.org/) -- major web companies, including Google, Facebook, Yahoo!, and Microsoft, will enable IPv6 on many of their websites for 24 hours to test how IPv6 performs in the real world. 

More than 99.9% of people shouldn’t have any problems during this industry-wide test, but your experience on June 8th will depend on your computer and network configuration.
- If you only have IPv4, you’ll simply use IPv4 as usual and not see any test-related problems.
- If your configuration is ready for IPv6, you’ll automatically use IPv6 and not see any test-related problems.
- In rare cases if you have IPv6 enabled but not configured properly, you may have connectivity issues with Google Apps and other test sites on June 8th.

If you’d like to start checking your organization’s IPv6 preparedness before June 8th, you can instruct your users to visit ipv6test.google.com from the devices, like primary work machines, tablet devices and home computers.  If you discover IPv6 connectivity problems, you can find troubleshooting tips and more information here: http://www.google.com/support/websearch/bin/answer.py?hl=en&topic=8995&answer=1299266

via Google Apps