Math.com Sudoku posts five new puzzles daily each graded from Easy to Fiendish. Each puzzle has an one unique solution and can be solved just with pure logic. Guessing is not required.
To learn more about Sudoku, see Wiki.
See also Play Sudoku online. A new Web 2.0 style website for Sudoku players
Play Free Online Chess Games. No downloads, it’s AJAX. You need just a browser to play with your friends and other people. No page refreshes – pieces move instantly. Chat. Rating.
Features:
Play as many games at once as you want
E-mail move notification (stay online and you’ll see opponents’ moves right away)
Switch between games in one click
View [...]
SudokuJunction.com – new Web 2.0 website, has been launched, allowing members to upload, share and play Sudoku puzzles over the internet.
Player can upload the puzzle through an easy to use uploading interface over the site. The puzzle without delay becomes accessible for anyone to play over the web.
The site supports a different of puzzle sizes, [...]