The Pokémon Communication Center

As You Can see, When you go into Goldenrod City, The Entire PCC was ripped out and replaced with just a normal Pokémon Center. For Those Of You Who wish to see what it looked like inside, here is a map

Left: Administration as seen in this pic

Center: Trade Center through Mobile
Right: Pokémon News Area.

Celebi: Lack Of,

Due To The Lack of the Mobile Adapter in the English Speaking Countries There Is No Way to get the GS Ball. But If There was these events will happen in short order (Also If you hack into the game with Gameshark codes I will add soon):
The nurse stops you on your way out. She says that if you can pass the test of collecting 16 badges, then you may have the GS Ball. Travel and collect the rest of the 16 Badges. Next, you must play and win the Chieko and Dice Game 3 times in a row. Then, you must correctly answer the 10 card quiz When you leave the PCC, you will receive the GS Ball. However, the GS Ball is a mysterious item, and cannot be used on Wild Pokémon. Instead, you must take it to an expert on Poké Balls.

Get the GS Ball back from Kurt. In Azalea Town, Kurt is surprised to see the GS Ball. He's never seen anything like it before, and would like to look at it for the day. The next day, Kurt hurries outside. Something it happening at Ilex Forest, and he returns the GS Ball to you. In Ilex Forest, the wind is blowing through the trees. Take the GS Ball and place it in the shrine of the forest's protector. Celebi will fly down from above above and attack. Celebi is on level 30, and you only have one chance to catch it. If you don't have a Master Ball, hopefully you've stocked up on Ultra Balls, or have Level Balls with a high leveled Pokémon

Odd Egg/Egg Card
Originally, the Old Daycare Man would give you an Egg Ticket that you would use to get an Odd Egg with a baby that knows Dizzy Punch, and has a 50% chance of being a Color Pokémon. Click Here for more information for the English Version

Battle Tower

To The West Of Olivine City There Is A Huge Battle Tower. In Tha Japanese version of the game you can battle people here and also utilize the Battle Feature through the Mobile Adapter. But it was altered so that in the English version you fight lots of people there but with level limits of 10, 20, 30, 40 and after you have done the Elite 4 and the Kanto Gyms, all up to 100. You can't get Experience In Here But you will get Prizes each time like HP Ups so get training