Appearing and disappearing hay barrels:
Play the first level. When you get to Gloria's Pad, kick open the left gate. Destroy the hay barrels in the Penguins' Pool then go back to Gloria's Pad. Look through the left gate and the hay barrels will be there. Go back to the Penguins' Pool and they will be gone.

Banquet:
Goto the main lemur that is on the drum where all the food lies. Talk to him 10 times in a row to earn food. This can only be done 2 times.

Flying Bird Mini-game:
When you are in level 3, go into the right subway entrance to find one of the arcade games.

Invincibility:
Press Up, Down, X(2), R1, L1, R2, L2, Triangle, Square, Circle during game play.

Level select:
Press R1(2), Circle, L2, L1, X, Triangle, R1, Triangle during game play.

Unlimited Items and bits:
This trick requires your main Digimon as player one and any Digimon as player two. Give all your Bits to player two. Then, save player two at the Save Keeper. Next, have player two give all Bits to player one. After that, have player two quit the game at the Save Keeper, but this time without saving. Then, go to Call Keeper and have player two join in again with the same Digimon. Repeat this from the beginning until you have 9,999,999 bits, both in the bank and pocket. You can also use this trick to duplicate items. This is very useful if you want to give some rare weapons and armor to a friend.