Pokemon Ruby Cheats

Get Mystery Event
After you beat the Elite Four, go to Petalburg City and talk to the man by the computer. He'll ask you for a profile. Tell him "Mystery Event Is Excited". After you're done talking to him, save your game and turn your GameBoy off and then back on. You'll now have the Mystery Event option unlocked.

Battle Tower Prizes
Complete tasks in the Battle Tower to earn the following prizes:

1-5 Victories:
Calcium
Carbos
HP Up
Iron
Protein
Zinc

6 or more Victories:
Bright Powder
Choice Band
Focus Band
King's Rock
Leftovers
Mental Herb
Quick Claw
Scope Lens
White Herb

50 Victories in a row:
Award Ribbon
Silver Shield

100 Victories in a row:
Gold Shield

Watch TV for Hints
Watch television to see commercials advertising bargains and the like. Here are some occurences to keep your eyes peeled for:
A commercial for the Mauville Game Corner. When it plays, head over there for increased prizes.
A commercial for the Lilycove Department Store. Get a discount after you see the commercial.
Pokemon sighting information. When the TV tells you a specific Pokemon is spotted, go to that location to find the monster in question.
A commercial for the Slateport City energy guy. Go to him to get energy items at a reduced price.

Passwords
Tell the Berry Master's Wife certain phrases to receive the following berries. You can only tell her one of these each day. You will receive a Spelon Berry.

GREAT BATTLE - You will receive a Pamtre Berry.
CHALLENGE CONTEST - You will receive a Watmel Berry.
OVERWHELMING LATIAS - You will receive a Durin Berry.
COOL LATIOS - You will receive a Belue Berry.
SUPER HUSTLE

Mirage Island
There is an island called Mirage Island. Mirage Island can only appear if you have a Mirage Island Sensitive Pokemon in your party. Mirage Island Sensitive Pokemon are found randomly in the wild like an ordinary wild pokemon. If you catch a pokemon and bring it to the man in Pacifilog town in the bottom most house he will tell you if you have a pokemon that can find Mirage Island.

How to get two rare berries every day
You have to go to sootopolis city. Go to the girl beside the three trees and talk to her and she'll give you two berries (you can only do this once a day.)

Bring Fossil to Life
Go to Route 111, go to the sandstorm, and go all the way to the right. There you will find two fossils--the Claw Fossil and the Root Fossil. Pick one, then go to Rustboro City. Go to the president's office and go in a room with lots of scientists. Talk to the one in the lower right hand corner. Then go outside and walk around for about 30 seconds and go back in to talk to the same scientist as before. He will give you your Pokemon from the fossil.

Jirachi
Get 200 pokemon to unlock Jirachi.