This was the scene in Tokyo as former Vice President Al Gore kicked off the Live Earth concert in Tokyo. Live Earth was held in venues all over the world -- even in Antarctica -- and was broadcasted to 2 billion people. The purpose of the concert was to raise awareness of the serious problem planet Earth faces from global warming and pollution. Here is the video featuring a holographic Al Gore. Al Gore is even beamed out at the end of his speech.
This type of holographic technology is expected to become more commonplace and eventually everyone will have their own telepresence. You can find more Live Earth resources here and here.
