Yeah, so I’m a decade behind the times. Just never got into the game, or even bothered to find out how to play. But today I decided to try. I finished it, but I’m still figuring out the logic…
There are some solving techniques that are not obvious at first glance, but only the more difficult sudokus require them.
Second one went a lot quicker.
Yeah, my first sudoku took about two hours, whereas now I’d probably finish it in about five minutes.
I’ve downloaded a free app to my iPod. To try it out, I chose an Easy one. I was making good progress when I accidentally touched the Back button and lost it. I started a new game and had one more square to fill, when my thumb accidentally clicked the Home button and I lost that one too. :smack:
This is a better time-waster than FreeCell! 
When you’ve OD’d on them, go on to the many variations. I like killer sudoku. http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/games_and_puzzles/killer_sudoku/
The FAQ tells me everything, except what’s “killer” about them. I launched one easy puzzle, and it came up with no numbers at all. I assume that’s part of the killerness.
This site gives a good rundown of the various solving techniques.