Press L + R + Start + Select during game play.
Beat the Elite Four once and go to the S.S Aqua ship in Olivine City to get the National dex.
Secret box wallpapers and Pokemon eggs
Go to the Violet City Pokemon Center. Notice the man next to the PC. Tell him certain words when he asks you for your opinion. Use this site to generate these words. This will unlock special box wallpapers and Pokemon eggs in your game.
Restart the Game
Simultaneously press L + R + START + SELECT to reset the game.
Change the Time and Day
Change the DS clock time to catch certain Pokemon at night and on certain days (like Monday, Wednesday and Friday for contests).
Rematch with Legendary Pokemon
If you accidentally kill a legendary Pokemon, don't panic. Just beat the Elite Four again and the legendary Pokemon will be alive and roaming again.
You can use the points from the Pokeathalon in the shop to buy certain items. These change from day to day, so look for elemental stones and rare candies in the shop (and you can use the DS calendar options to change the day of the week).
Quick Radio Tower
At one point you are required to dress up as a Rocket to get to the radio tower. After you are told you have to get the key from the director, instead of taking the card key and battling the grunts, just head to floor B1 in the Goldenrod department store, head to the stairs, and you'll find the director. Battle the grunt and you're done.
Game Boy reference
At Celadon City, enter the Celadon Condominiums next to the Pokemon Center. Use the elevator to reach the third floor. When you exit, your friend will tell you about the GB Sounds. Talk to the man next to the globe after collecting all of the Kanto badges to get the GB Sounds Device.
Dragon Ball Z reference
In Ecruteak City at the Dance studio, a Team Rocket grunt is hassling a kimono girl. Talk to the person on the right side of the stage. He tells you he would have put a stop the grunt's behavior if it was not for the incredible pain of his stomachache. This is a tactic commonly used by Hercule Satan in Dragon Ball Z to get out of fighting.
Ruins of Alph: Hidden items
In the same rooms where you have to complete a picture puzzle of Omanyte, Kabuto, Aerodactyl, or Ho-Oh, there is a plaque that has a word that is spelled using Unowns. Do the following steps.
• Room with the Kabuto Puzzle: The word is "Escape". You must use an Escape Rope facing the plaque. You can easily get an Escape Rope at the Violet City Pokemart. The four items obtained are Energy Powder, Heal Powder, Oran Berry, and Pecha Berry.
• Room with the Aerodactyl Puzzle (accessible by Surfing): The word is "Light". Use Flash while facing the plaque. The four items obtained are Energy Root, Heal Powder, Moon Stone, and Sitrus Berry.
• Room with the Ho-Oh Puzzle: The word is "Ho-Oh". You must have Ho-Oh first in your roster. The items obtained are: Charcoal, Leppa Berry, Life Orb, and Revival Herb. In Pokemon HeartGold, Ho-Oh is obtained in the Bell Tower. In Pokemon SoulSilver, Ho-Oh is obtained after you have defeated the Elite Four.
• Room with the Omanyte Puzzle: The word is "Water". You must have a Water Stone in your bag. The items obtained are: Leppa Berry, Mystic Water, Stardust, and Star Piece. A Water Stone can be obtained by winning it at the Pokeathlon on Wednesday.
Trainer Card colors
Complete the indicated task to unlock the corresponding color. You can earn stars by completing the following tasks: defeating the Elite Four, finding all Shining Leaves, and capturing all 493 Pokemon (not including event-only Pokemon).
#. Unlockable: --- How to Unlock:
1. Black Card --- Earn five stars.
2. Blue Card --- Earn one star.
3. Bronze Card --- Earn two stars.
4. Gold Card --- Earn four stars.
5. Silver Card --- Earn three stars.
Unlockable Pokewalker Maps
There are over 20 Pokewalker maps currently available to anyone and everyone who owns them. The trick is obtaining Watts and getting the National Dex. Note that some of the following are event-only, so the Yellow Forest (for example), is unattainable right now.
#. Unlockable: --- How to Unlock:
1. Beautiful Beach --- Obtain 200 Watts
2. Beyond the Sea --- Obtain a foreign pokemon via use of the GTS
3. Big Forest --- Obtain 40,000 Watts and own the National Dex
4. Blue Lake --- Obtain 2,000 Watts
5. Dim Cave --- Obtain 1,000 Watts
6. Hoenn Field --- Obtain 5,000 Watts and own the National Dex
7. Icy Mountain Rd. --- Obtain 30,000 Watts and own the National Dex
8. Night Sky's Edge --- Trade a fateful-encounter Jirachi onto your HG or SS
9. Noisy Forest --- Available from the start
10. Quiet Cave --- Obtain 100,000 Watts and own the National Dex
11. Rally --- Wifi Event from January 29th to February 28th, 2010 (Japan)
12. Refreshing Field --- Available from the start
13. Resort --- Obtain 80,000 Watts and own the National Dex
14. Rugged Road --- Obtain 50 Watts
15. Scary Cave --- Obtain 20,000 Watts and own the National Dex
16. Sightseeing --- Wifi Event from November 14th (2009) to to January 11th (2010) in Japan and from April 17th to May 31st, 2010 in Korea
17. Sinnoh Field --- Obtain 25,000 Watts and own the National Dex
18. Stormy Beach --- Obtain 65,000 Watts and own the National Dex
19. Suburban Area --- Obtain 500 Watts
20. Town Outskirts --- Obtain 3,000 Watts
21. Tree House --- Obtain 15,000 Watts and own the National Dex
22. Volcano Path --- Obtain 10,000 Watts and own the National Dex
23. Warm Beach --- Obtain 7,500 Watts and own the National Dex
24. White Lake --- Obtain 50,000 Watts and own the National Dex
25. Winner's Path --- Wifi Event from May 6th to June 25th, 2010
26. Yellow Forest --- Wifi Event from April 1st to May 5th, 2010
Unlockable Pokewalker Routes
With regular usage of the Pokewalker included with SoulSilver, you can obtain Watts that can be used to unlock special courses that hold unobtainable Pokemon in both HeartGold and SoulSilver versions. Watts are not total obtained, but collected in the game after returning from a stroll or sending gifts back to your game. There are also several routes unlocked by Nintendo Wifi Events and specific Pokemon.
#. Unlockable: --- How to Unlock:
1. Amity Meadow --- Unreleased to all versions.
2. Beautiful Beach --- Collect 200 Watts.
3. Beyond the Sea --- Trade for an International Pokemon in the GTS in Goldenrod City.
4. Big Forest --- Collect 40,000 Watts + National Dex.
5. Blue Lake --- Collect 2,000 Watts.
6. Dim Cave --- Collect 1,000 Watts.
7. Hoenn Field --- Collect 5,000 Watts + National Dex.
8. Icy Mountain Road --- Collect 30,000 Watts + National Dex.
9. Night Skys Edge --- Obtain the PokeDex Data for Jirachi.
10. Quiet Cave --- Collect 100,000 Watts + National Dex.
11. Rally --- Unreleased to U.S. versions.
12. Rugged Road --- Collect 50 Watts.
13. Scary Cave --- Collect 20,000 Watts + National Dex.
14. Sightseeing --- Unreleased to U.S. versions.
15. Sinnoh Field --- Collect 25,000 Watts + National Dex.
16. Stormy Beach --- Collect 65,000 Watts + National Dex.
17. Suburban Area --- Collect 500 Watts.
18. The Resort --- Collect 80,000 Watts + National Dex.
19. Town Outskirts --- Collect 3,000 Watts.
20. Treehouse --- Collect 15,000 Watts + National Dex.
21. Volcano Path --- Collect 10,000 Watts + National Dex.
22. Warm Beach --- Collect 7,500 Watts + National Dex.
23. White Lake --- Collect 50,000 Watts + National Dex.
24. Winner's Path --- Nintendo Wifi Mystery Gift from 05/06/10 to 06/25/10
25. Yellow Forest --- Nintendo Wifi Mystery Gift from 04/01/10 to 05/05/10