http://www.sudoku.org.uk/
http://www.sudoku.com/
http://www.sudoku-xls.com/
http://www.websudoku.com/
http://www.dailysudoku.co.uk/
http://www.miniclip.com/
http://www.coolquiz.com/*
http://www.funtrivia.com/
www.queendom.com/mindgames/quizdom/
http://www.puzzles.com/
http://www.quizbrain.com/
http://www.braingle.com/
http://www.crossword-compiler.com/