It's the hottest game around. Not to mention a fashion trend (people will put anything on a t-shirt). Simple in design, this number game requires logic and a good bit of luck. The name "Sudoku" is the Japanese abbreviation of a longer phrase, "Suuji wa dokushin ni kagiru," meaning "the digits must remain single." Challenge yourself to the daily Catalyst Sodoku online at catalystconference.com and click on the submarine icon. Warning: this game has addictive properties? Do you sodoku?