Here's another link to a daily:  http://www.dailysudoku.co.uk/sudoku/

And here's one with a speed challenge : http://www.sudokufun.com/

Interestingly, when I'm having difficulty thinking something through, I do one of these and by the time I'm done, I have a better clarity on the issue. Often have a similar experience with playing spider solitaire (multiple decks).

I also had a dream about them once I started doing them, and the message or insight was that a properly completed SudoKu is akin to a truth about the universe: there is only ONE true self for each of us, just as there is only ONE right answer for each position in the SudoKu grid. And when we each realize our TRUE self, we find our proper place in the "grid", relate perfectly and harmoniously to every other position, and the big picture becomes clear. *heehee* The implication in the dream, though, was that until that happens, the big picture will not be clear.

~Sowelu

http://www.fingertime.com/sudoku.php