Final Fantasy Crystal Chronicles

Get Lots of Gil
Enemies in the Lynari Desert (cycle three) drop 1200 Gil.
In the same area, the giant birds drop an item called Orichicalcum, which can be sold for thousands of Gil..
(Thanks to gestahls_master@yahoo.com)

Get Lots of Gil
Start a saved file with a character that you are going to want to keep and three characters that you do not intend to keep. Once all the characters are chosen, go back into Tipa. With the three characters that you do not want to keep, drop the 200 Gil that you start with along with all items that can be dropped. Go into Tipa with the character that you do want to keep and pick up all of the dropped items and Gil. You should pick up 600 Gil each time you repeat this.
(Thanks to gestahls_master@yahoo.com)

Get Lots of Gil
You’ll need two memory cards and the compatibility for multiplayer (at least two GBAs and at least two GameCube-to-GBA cables).
1. Once you reach Alfitaria, look for a Lilty-looking soldier named Knocfelna and speak to him. He will tell you a little about Alfitaria's princess.
This starts a sequence of events that you must progress through in order to complete this cheat.
2. Speak to Te Odow, a peddler in Marr's Pass.
3. Bump into the disguised princess at Jegon River.
4. Encounter Knocfelna at Jegon River.
5. Speak to the princess and Knocfelna in the Fields of Fum.
6. Encounter the princess and Knocfelna in Leuda.
7. Exit Leuda BY LAND to watch a movie about the princess.
8. Save your game at this point here.
9. Enter Alfitaria to watch the final movie sequence. You will receive 100,000 gil for every character that's involved in Step 9.
Now, save the game and copy your Crystal Chronicles file onto another memory card. Turn the game back on and import a character that received the 100,000 gil from one memory card to the one that you are now playing on. Enter a level with at least two characters and drop the 100,000 gil from one character and pick it up with the other. After giving all of the gil to one memory card, delete the extra file and copy the original again. Now when you go to do the cheat again, the character has at least 200,000 gill to drop. Repeat the deleting and copying cheat for as much Gil as you want.
(Thanks to gestahls_master@yahoo.com)