Assassination gun

Cigarette case weapon

Hidden knives

Fairbairn-Sykes fighting knife

Keychain guns

Silenced firearms

Poison-pellet weapons

Single-shot pistol

The 'Stinger'

Suicide weapons

Dead-drop bolt

Dead-drop spike

Bugs

Bug detectors

Corona

Cray Supercomputer

Hollow coin concealment

Fiber-scope

Hidden still cameras

Hidden video cameras

Infrared telephone

Invisible ink

Hidden audio recorders

Microdots

Minox camera

One-time pad

U-2 Spy Plane

SR-71