Thanks to Leigh Anne for sending a link along to the website of the Sudoku 2007 2nd World Sudoku Championship in Prague (Czech Republic).
Here you can find a lot of information about the World Sudoku Championship, but the best thing is that there is a 34 page pdf document [750kb] which you can download for free with a lot of Sudoku variants (Jigsaw Roundoku, Futoshiki, IsoSudoku and much more) and also examples you can expect at a World Sudoku Championship.
Enjoy all Sudoku puzzle variants or just practice your skills for the 2nd World Sudoku Championship. Thanks again to Leigh Anne for sending along. Happy Puzzling!