I love Sudoku. I especially love doing this Sudoku:

http://games.latimes.com/index_sudok...ure_code=lasud

You can erase easily, you can write notes in the squares and there's a hints option that can help to teach you the logic. the puzzles are typically easier on Mon and get harder as the week progresses until you get the killer weekenders.

A great way to spend and hour or two.