I've never understood the hype around the Sudoku puzzles, or maybe I simple never paid attention to it. But recently, while visiting my parents, my father told me about his newest addiction. Due to his enthousiasm, I've tried one myself. It's a bit getting used to, but eventually it worked for me as well. In the mean time, we bought a whole pocket bock full of Sudoku puzzels at some kiosk ranging from 1 to 4 stars.
Well, I'm officially addicted now. I've started with a few 1-star puzzles but worked myself up to the 4-star ones. Since these are usually too difficult to solve without making a lot of notes, I was looking for some nice Sudoku templates that have a bit more space.
My search completed with a great article by Michael Mepham about several advanced techniques for solving a Sudoku. And his articles provides some great worksheets as well. I suppose you can call somebody who performs research on how to solve Sudokus addicted, shouldn't I?
Update 28-02: Check out this link. It's an online Sudoku game that you abuse for solving your paper-based Sudoku's as well.