Well in the iTunes store, there's a new game for the iPod called Sudoku, made by EA games. Its description: "Solve the Grid in a Zen setting"
I'm not interested in iPod games actually, 5 bucks a piece is a rip-off (5 Euros for those in Euroland) but this caught my eye enough for me to read the description.Here
's a little review (even though, in my opinion, clickwheel +grid+9 numbers=suck)
It has a relaxing background, Japanese-inspired relaxing sounds, and (if I read this right) hints you at easy-to-solve boxes.
I'm not too familiar with the multitude of Sudoku spinoffs, but something tells me that EA got slightly inspired off of UWE for their Sudoku game