Instructions
Deposit at least 10,000 bells into your bank account. Save and turn off the Wii console.
Turn on your Wii console and click "Wii Options." Select "Wii Settings" and then "Calendar."
Set your calendar to June 2, 2000. Hit "Confirm" to save.
Load "Animal Crossing: City Folk" and select your save file.
Quit the game and save your file. Turn off the Nintendo Wii again, then boot it back to the home menu.
Go back to the calendar settings and change the date to June 2, 2035.
Load your "Animal Crossing" save again. You will earn 35 years of interest on your money.