Sudoku took the UK population by storm. It was the puzzle revelation of 2005. Whatever would come next? Well, here is the answer: Kakuro. From the makers of Sudoku come these tough little puzzles that require you to fill in numbers between 1 and 9 into a grid. This time though, the numbers have to add up to the totals given in boxes on the side and you can't have the same number twice in the same row or column. It sounds simple, and it is...but so was Sudoku!