A crossword a day keeps insanity at bay. That, as my old grandmother used to put it, was derived from an ancient Confucian proverb about the importance of keeping an active mind. For, like the best well-oiled machine, one's grey matter needs regular exercise and plenty of maintenance to keep it tikkety-boo.

Gizmos of the like of the Sudoku Toilet Roll are designed to sharpen your mind in the smallest room in the house. Now you can sharpen your mind and hone your mental brilliance in the largest room in the house. Or most likely, unless your house resembles Beckingham Palace, outside your house with your little brother clutching one end from the highest window and you on the ground gradually working your way up - Rapunzel-style.

You see this is no ordinary crossword puzzle book. In fact this is the world's tallest crossword book - four storeys high (12.8m) to be precise. The gigantic concertina format has enabled the bright folks at peacefully named Lagoon to squeeze the world's tallest crossword onto its pages for hours and hours of puzzling (and rather addictive) fun.

Once upon a time, one had to rely on the ultra-clever and ultra secretive setters of newspaper crosswords for company on a wet Wednesday in November. Let's take a stand fellas - get yourselves a tallest ever crossword book and give newspaper crosswords a well deserved snub.