Two sheets of Chinese blue military stamps from Chinese philatelist Li Shuguang's collection is displayed during the 2006 World Philatelic Exhibition in Washington, capital of the United States, June 2, 2006. Li won a Gold Prize and a Large Gold Prize at the exhibition, which would close on June 3, 2006. Twelve albums and 84 frames of stamp productions from China were displayed during the exhibition. (Xinhua Photo)

The world's first postage stamp, the One Penny Black, is seen at the 2006 World Philatelic Exhibition in Washington, capital of the United States, June 2, 2006. About 4,000 frames of philatelic material from over 70 countries and regions were shown during the expo held from May 27 to June 3. (Xinhua Photo)