Here’s an idea for an entrepeneur.Create a two-person Sudoku game. My idea is this:

Instead of numbers, use colors. It looks nicer, and I think it would be more fun.

Have an electronic board that generates the puzzles and keeps track of each player’s time. When the game starts, it’s the first player’s turn. His clock is running. He selects a color and places it on the board (by pushing on the spot–the electronic board will sense both the color he picked and the place he marked). If his placement is correct, it is the other player’s turn. The other player’s clock starts, and he selects a color and places it on the board. Play continues until one player runs out of time (loss) or makes an incorrect move. If the puzzle is solved with neither player losing, it is a draw.

By the way, I think that the linked article does not talk about my strategy. I am number-focused, rather than cell-focused. That is, I look for 8’s, and then try to find ways in which the existing 8’s force a particular cell to have an 8.