Sources of Information
US Puzzle and Sudoku Championships
US Puzzle Championship website, home of the US Puzzle Team and qualifying for the World Puzzle and Sudoku Championships.
World Sudoku Championship - Wikipedia
The World Sudoku Championship is an annual international sudoku competition organised by a member of the World Puzzle Federation. The first one was held in Lucca in 2006.
Fifth World Sudoku Championship - PuzzleWiki
The Fifth World Sudoku Championship will be held April 29 - May 2, 2010 in Philadelphia, USA. The Championship will last for sixteen rounds, ten individual rounds, five team rounds, and the individual finals.
When you think of big international competitions that bring a lot of national pride with them, Sudoku is probably not the first thing that jumps to mind.
And don't forget to check your skills before you go to the Sudoku Championship.