I read an article in the Denver Post this week regarding Sudoku Puzzles. I then completed several puzzles at websudoku.com.
You can create and solve sudoku puzzles using an MS Excel work book from Andy Pope: AJP Excel Information – Su Doku puzzle.
I also found a Sudoku puzzle solver at Office Online via Daily Dose of Excel.
More Sudoku linkes : http://www.sudokufun.com/ and http://sudoku.heebie.co.uk/