There are actually two ways to clone a pokemon. The First Way is:
1.Go to Viridian City and talk to the man who shows you how to catch a pokemon.
2.When he asks you if your in a hurry say no once the say yes once.
3.Put the pokemon you want to be cloned as your 4th pokemon.
4.Fly to Cinnabar Island and surf on right side coast and catch an M' at level 0.
5.It will still be there so catch it again it is a ditto.
6.Go to your pokemon box and release the M' and withdraw the ditto.
7. The Ditto should be the same as your 4th pokemon.
The 2nd way is easier:
1.Hook up with a game link cable to your friends game to trade.
2.If 1 person has a pokemon that you want do this.
3.The 1 that doesn't have the rare pokemon trade a rattata.
4.When the trade is almost done the person who originally had the strong or rare pokemon when the screen says waiting turn your gameboy off before it says "trade complete".
5.Then the person with their gameboy on waits till it says"trade complete" and then turns their gameboy off.
6.When you turn your gameboys back on you should both have the rare or strong pokemon and the common pokemon should be gone
Submitted by Clint McRay The Pokemon Man (firstname.lastname@example.org)