Editor’s Note: To promote the mental_floss Holiday Subscription Special, I’ve asked co-founders Will Pearson and Mangesh Hattikudur to select some of their favorite mag articles from 2008. Today’s story comes from Beth Bartlett. And if it puts you in a subscription-giving mood, here are the details.

By Beth Bartlett
November-December issue

1. Slinky

No toy seems to exhibit a fear of heights the way the Slinky does. Place the cowardly coil on the top of a staircase, and it immediately starts inching its way down. But in battle, this spiral wonder has proven far braver. In Vietnam, the toys worked from treetops. Radio operators would tie rope through the middle of the long metal spirals, then drape them over branches to create perfect radio antennas. The Slinkys were especially useful because they didn’t tangle and could be yanked down quickly when soldiers needed to run. Of course, if you’re off to battle, buy an extra. While one Slinky will do the job, most radio operators wielded two for better reception.

2. Metal Crickets

During the D-Day invasion at Normandy, more than 15,000 men dropped from the night sky carrying little metal insects. At the time, flashlight signaling was a common way for soldiers to communicate, but officials worried that flashing lights could tip off observant Germans. So, they substituted the torches for cheap, wind-up crickets that made clicking sounds. Each paratrooper received one, along with instructions to identify himself through the chirps. The brilliant scheme helped soldiers meet up safely on the ground. Unfortunately, the success was short-lived. A few Germans caught on, and after capturing some of the crickets, they used them to trap unsuspecting Americans. Still, the toys contributed to the invasion’s success, and souvenir replicas are still sold to tourists in Normandy today.

3. Silly String

Since the start of the Iraq war, worried families have sent tens of thousands of Silly String cans to their sons and daughters in the military. Why? Shortages of night-vision goggles have forced soldiers to improvise with the fluorescent foam. Silly String is especially good for finding tripwires in the dark. Before entering suspicious rooms, soldiers spray the string everywhere. If the glowing blobs hang ominously mid-air or get stuck on previously invisible objects, soldiers know to tread lightly.

4. The View-Master

The View-Master was originally for grownups. Developed in the late 1930s, the device was used as a training tool to help WWII soldiers recognize specific ships, planes, and artillery from afar. But after the war, the device got a kid-friendly makeover. The toy was outfitted with reels featuring television characters and tourist destinations, and it quickly became a staple in toy chests everywhere.