Duplicate Items
First, fly to Viridian City and talk to the old man that tells you how to catch a pokemon and when he asks you a question, answer no. As soon as he is done talking, fly to Cinnabar Island and surf on the right edge of the island (the side where the gym is) and you will run into a Missingno. Do not catch it! Send out a pokemon and make it faint. Look at the 6th slot of your item list and that item will be duplicated if there is a glitchy picture there instead of a number. (This code does not mess up your game, but if you catch the Missingno pokemon, your game will be messed up like there is no tommorow! (Try putting a Rare Candy, a Nugget, or a Master Ball!).
Submitted by GR0UD0N. 

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