Ok My first cheat is that if you trade any Arceus ( You can do this twice once with Hacked/cheated Arceus or Event Arceus) to HG or SS you need to go inside the building at Ruins Of Alph with Arceus the first pokemon in your party. Follow the man that bumps into you into the ruins. Then you will be teleported to the Sinjoh Ruins the ruins between Johto and Sinnoh. Follow the hiker to the house. Once you get there, put all your pokemon in the pc box except Arceus. Then follow Cynthia (from Sinnoh) back to the ruins. She will talk to you and tell you to walk up on the stage. Walk up on the stage and you will be given the chance to get either Dialga, Palkia, or Giratina. (all lv.1) Choose one and it will play a video. After it's done, you will have an egg in your party. (Note: you don't have to even have beaten the eighth gym leader yet to do this)
Well, I hope this helps! (Tested and works) Post your cheats or glitches here too.
Ok, anyone who didn't get the secret key in pokemon platinum don't worry. First, trade a rotom to HG or SS and go to the Silph Co. building in Kanto. Have Rotom first in your party and press A on the elavator. Rotom will power up the elavator and it will take you to a room with several red objects. Press A on the object you want Rotom to posess. He will posess it. There is a fan, a lawn mower, a refrigerator, and an oven. I chose a lawn mower because when Rotom is the first pokemon in your party, he looks like an out-of-control lawn mower is chasing you! Lol. (Have you ever noticed spelled backwards Rotom is motor? XP )