Current Leader of the World (24.02.2008)

The List is far from complete and will be extended from time to time. For each country I know, I underlined the person, who has the most powerful office - head of state or chief of government.

Country Head of State Title Chief of Gouvernment
Afghanistan Hamid Karsai (1957), since 2001 President -
Antigua and Barbuda Elizabeth II (1926), since 1952 Queen Baldwin Spencer (1948), since 2004
Armenia Serzh Sarkisyan (1954) President Tigran Sarkisyan (1960)
Austria Heinz Fischer (1938), since 2004 Federal President Alfred Gusenbauer (1960), since 2007
Belgium Albert II (1934), since 1993 King Yves Leterme (1960) since 2008
Belize Elizabeth II (1926), since 1952 Queen Dean Barrow (1951), since 2008
Bosnia and Herzegovina Haris Silajdzic (1945) since 2008 President Nikola Spiric (1956) since 2007 
Botswana Ian Khama (1953) President -
China, Republic of Ma Ying-jeou (1950), since 2008 President Liu Chao-shiuan (1943) , since 2008
Costa Rica Oscar Arias Sánchez (1941), since 2006 President -
Cuba Rául Castro (1931), since 2008 President Rául Castro (1931), since 2008
Denmark Margarete II (1940), since 1972 Queen Anders Fogh Rasmussen (1953), since 2001
Egypt Hosni Mubarak (1928), since 1981 President Ahmed Nazif (1952), since 2004
France Nicolas Sarkozy (1955), since 2007 President François Fillon (1954), since 2007
Germany Horst Köhler (1943), since 2004 Federal President Angela Merkel (1954), since 2005
Guinea Lansana Conté (1934), since 1984 President Ahmed Tidiane Souaré (1951) , since 2008
Hungary László Sólyom (1942), since 2005 President Ferenc Gyurcsány (1961) since 2004
Ireland Mary McAleese (1951), since 1997 President Brian Cowen (1960), since 2008
Italy Giorgio Napolitano (1925), since 2006 President Silvio Berlusconi (1936), since 2008
Japan Akihito (Heisei) (1933), since 1989 Emperor Yasuo Fukuda (1936), since 2007
Kosovo Fadmir Sejdiu (1951), since 2006 President Hashim Thaçi  (1969), since 2006
Kuwait Sabah Al Ahmad Al Jabir Al Sabah (1929), since 2006 Emir Nasser Muhammad Al Ahmad Al Sabah (1941), since 2006
Libya Muftah Muhammad Kaiba (since 2008) Secretaries of the General People's Congress Al-Baghdadi Ali al-Mahmudi(1945) since 2006
Mauretania Sidi Mohamed Ould Cheikh Abdallahi (1938), since 2008  President Yahya Ould Ahmed El Waghef (1960), since 2008 
Nepal Girija Prasad Koirala (1925), Since 2008 President Girija Prasad Koirala (1925), since2006
Pakistan Pervez Musharraf (1943) since 2001 President Yousaf Raza Gilani (1952) since 2008
Peru Alan García Pérez (1949), since 2006 President Jorge del Castillo (1950), since 2006
Russia Dmitry Medvedev (1965), since 2008 President Vladimir Putin, since 2008
Sáo Tomé and Principe Fradique de Menezes (1942), since 2001 President Patrice Trovoada (1962), since 2008
San Marino Rosa Zafferani (1960) and Federico Pedini Amati (1976), since 2008 Capitani Reggenti -
Sao Tomé and Principe Fradique de Menezes (1942), Since 2001 President Joaquim Rafael Branco (1953), since 2008
Saxonia (Germany) Stanislaw Tillich (1959), since 2008 Ministerpresident -
Slovakia Ivan Gasparovic (1941), since 2004 President Robert Ficeo (1964), since 2006
Slovenia Danilo Türk (1952), since 2007 President Janez Jansa (1958), since 2004
Spain Juan Carlos I (1938), since 1975 King José Luis Rodríguez Zapatero (1960), since 2004
Tansania Jakaya Kikwete (1950), since 2005  President Mizengo Pinda (1948, since 2008
Thailand Bhumibol Adulyadej (Rama IX) (1927), since 1946 King Samak Sundaravej (1935), since 2008
United Kingdom of Great Britain
 and Northern Ireland
Elizabeth II (1926), since 1952 Queen Gordon Brown (1952), since 2007
United States of America George W. Bush (1946), since 2001 President -
Uruguay Tabaré Vázquez (1940), since 2005 President -
Vietnam Nguyen Minh Triet (1942), since 2006 President Nguyen Tan Dung (1949), since2006