Metal Gear Solid 3: Snake Eater/Items

Cigar
Snake's favorite brand of Cuban cigars. Still hazardous to your health, and also usable as a light source in dark areas.

Fake Death Pill
A special pill designed by the CIA to put a person into a state of fake death. Use this in the menu to kill yourself. Enemies will believe you to be dead. When they walk away, use the Revival Pill to wake up again. Don't stay dead for too long, though, or the fake death will become real death. (Also useful if you want to restart an area, though be advised that any alerts or kills will remain even after continuing.)

Revival Pill
An even more special pill designed by the CIA to bring a person back to life after they've killed themselves with the fake death pill. It's disguised as one of your molars, and weighs absolutely nothing, so you can't remove it from your inventory.

Active Sonar
A special radar that sends out a sonar ping to detect local wildlife. Press L3 to send out a sonar ping. Be warned though - each ping takes a small portion of your batteries, and the noise it makes may alarm nearby guards.

AP Sensor
Much like the AP Sensor from MGS2, this will cause the controller to vibrate whenever a guard is nearby. This time, however, it requires batteries to operate (though not very much).

Scope
A pair of binoculars with a zoom lens. While equipped, press Triangle to zoom in, and Square to zoom out. You can also peek around by holding R1 and using the L2 and R2 buttons, just like in First Person View.
 * A special trick you can do with the scope: aim at a guard with the scope (it has an aiming crosshair, strangely enough), equip any projectile weapon, press L2 to unequip the scope and quickly hold the R1 button so your view doesn't reset. You can now fire your weapon exactly where the scope was aiming.