The Gamemode Command

The /gamemode command is a command normally used in creative-mode and adventure map worlds.

Overview
/gamemode basically changes your gamemode. You know how in the beginning of a world, it gives you the choices for the gamemodes of Creative, Survival, and Adventure? Yeah, this basically allows you to do that at will. (With the added bonus of Spectator.)

Syntax
/gamemode

Explanation
The gamemode value is the gamemode you want to change to. You can also use numbers. (0=Survival, 1=Creative, 2=Adventure, 3=Spectator)

Trivia

 * How to cheat in survival!
 * I honestly don't know what more to put.