Berry Master's Wife
The game features items called berries which are mixed with other ingredients to help raise a Pokemon's condition. You can find these by talking to the Berry Master's wife and inputting phrases. Five types of berry exist in total, and you can only enter one phrase per day; enter the phrases in capital letters. The phrase "Super Hustle" will grab you a Belue Berry, "Cool Latios" gets you a Durin Berry, while for a Pamtre Berry, enter "Challenge Contest." If you'd like a watmel berry, try "Overwhelming Latias," and for a Spelon Berry, enter "Great Battle."
Trainer Card Color Upgrades
You can increase the rank of your trainer card by accomplishing tasks in the game, and the card will change color too. Some of these tasks can't be performed until after you've finished beating the Elite Four at the storyline's end. You can advance in rank by completing your Pokedex, by collecting all of the gold symbols in the Battle Frontier area, by becoming champion at the Pokemon league and by besting all five Master Rank contests and winning a ribbon in each.
Lati
The Lati Pokemon -- Latios and Latias -- are two creatures which are difficult to find in the game, but can be obtained by following a particular method after you've beaten the Elite Four and finished the primary game plot. Enter your house, where you'll find a television. Then talk to your character's mom, who will ask a question with two answers: blue or red. Answering blue will get you Latios, and red will yield Latias.
Second Effects
Many of the game's Pokemon abilities actually generate two effects when given to the first Pokemon in your party, with these secondary effects not always immediately obvious. For example, if you equip the Magnet Pull power on a member of your party, you'll find that you encounter more steel-type Pokemon in the game's wilderness areas. The powers Keen Eye and Intimidate reduce random encounters in the wilderness by 10 percent when equipped to the first Pokemon in your group, while Hustle attracts wild Pokemon which have a higher level than that of the party member equipped with this power. Equipping Cute Charm, meanwhile, is more likely to yield encounters with wild Pokemon of the opposite gender to the monster you've given this power to.