When the 32 bit IPv4 standard was introduced in September 1981, it supported over 4 billion potential addresses. However, by February 2011, IANA reported that the existing supply of IPv4 had been fully allocated. 

IPv6 represents a 128 bit network addressing scheme and on June 8, 2011 this was launched in a 24 hour test by top vendors around the world.  This new addressing scheme requires new equipment, firewalls, and software interfaces.  The first test was successful and it will continue to emerge as an important standard for the future.

IP V6 Day – June 8, 2011
http://www.ipv6day.org/action.php
http://www.worldipv6day.org/

Test your PC for IPv6 capabilities
http://test-ipv6.com/

QUOTE: On 8 June, 2011, top websites and Internet service providers around the world, including Google, Facebook, Yahoo!, Akamai and Limelight Networks joined together with more than 1000 other participating websites in World IPv6 Day for a successful global-scale trial of the new Internet Protocol, IPv6. By providing a coordinated 24-hour “test flight”, the event helped demonstrate that major websites around the world are well-positioned for the move to a global IPv6-enabled Internet, enabling its continued exponential growth.