Change your DNS server to 2001:4860:4860::8844 (it's a Google opendns alternative) and you will get all Google related sites (search, maps, images, gmail) with IPv6, YouTube also (opendns servers does not give you that posibility), so you will be able to check real things with IPv6 not only special sites for testing purposes.
Slashdot Mirror
Change your DNS server to 2001:4860:4860::8844 (it's a Google opendns alternative) and you will get all Google related sites (search, maps, images, gmail) with IPv6, YouTube also (opendns servers does not give you that posibility), so you will be able to check real things with IPv6 not only special sites for testing purposes.