Heaneyland!

If you want to try out something new in sudoku, try shendoku, using the sudoku rules but playing two people, one against the other, like battleshipps. They have a free version to download at http://www.shendoku.com/sample.pdf . Anything else they are bringing out or they are working on you can find at www.shendoku.com or at they´r blog www.shendoku.blogspot.com . Have fun, I am. I specially like one slogan I heard about Shendoku: SUDOKU is like masturbation (on your own)…. SHENDOKU is like sex (it takes two).

This looks like a spam comment (albeit a relevant one), but I'll leave it up since I actually have a response, which is: sudoku is not very well-suited to a 2-player format. This looks a bit better than most, but it's unclear on some points -- like, say you decide you don't need to ask for any more squares. Since you and your opponent alternate asking for squares, is your opponent then locked out of asking for squares, or does he do so according to a pre-agreed-upon time limit (since, if there is no time limit, there's no penalty for him to just ask for information as quickly as possible)?