XM-8

It's almost scary how high-tech the military is getting these days, and Heckler & Koch are working on a futuristic replacement for the venerable M-16 rifle called the XM-8 that has interchangable barrels for converting it from an assault rifle to a sharpshooter to a compact submachine gun on the fly, attachable grenade launcher and 12-gauge shotgun, and swappable skins for changing colors that a soldier can change depending on whether they're fighting in a city, jungle, or desert

[Thanks, Noah]

DIY remote controlled Bluetooth car