You don't have to be a Bond junkie to enjoy a crafty spy gadget.

To appreciate spy gadgetry, though, you must be able to separate fact from fiction, meaning it's important to know what tools are thought up by Hollywood studios and what ones are actually used in the field.

Over time, of course, espionage agencies learned they must constantly innovate or risk falling behind their foes. While the ancient Greeks, for example, used cylindrical wood cyphers called scytales to transmit secret messages, the National Security Agency had access to devices like a modified USB connector called a Cottonmouth that can surreptitiously gain access to guarded networks and possibly attack them.

In the time that passed between the scytale and the Cottonmouth, spies and governments devised sundry devices and methods for sleuthing. During the Revolutionary War, colonial spies thought up the precursor to invisible ink and also created hollow bullets that held military orders. In World War I, intelligence agencies actually rigged pigeons with cameras to capture troop movements. Then, during the Cold War, Russian agents used cyanide gas guns and umbrellas tipped with ricin.

Think those gadgets and weapons sound cool? Check out the below infographic to discover more facts about these real-life gadgets and to learn about many more.