In case you couldn’t tell from the invisible ink article, I love all think spy-related. So this book, Mini Weapons of Mass Destruction 2, looks like a lot of fun. It provides step-by-step instructions on how to build 30 different mini spy weapons and surveillance tools using household items and office supplies. Learn how to make things like a pen blowgun, a paper dart watch, and a toothpaste periscope. This is the sequel to the first Mini Weapons of Mass Destruction, which included instructions on how to make things like a spoon catapult and a clip crossbow:
These books would be a cool present for a boy in your life, or for the man who needs to protect his lunch from thieves at work.