Leonardo da Vinci’s most famous creation is undoubtedly the Mona Lisa, but the artist was also a brilliant engineer who concocted endless contraptions including some formidable machines of war. This tiny trebuchet he designed won’t take down a castle, but it can almost certainly protect your desk from office supply raiders.
You might even learn a thing or two about engineering while you build this $25 (£17.25) kit that comes with all of the wooden parts pre-cut, and everything else you’ll need to assemble it. So even though you’ll probably use it to hurl paper clips and pennies across your office, your boss couldn’t possibly get mad at you because you’re also learning new and valuable skills for the workplace. [ThinkGeek]