For the GBC (Game Boy Color) I don't know of any hacks...
For any GBA (Game Boy Advanced) games, you use a GameShark...
For any DS (Dual Screen) game, you use the Action Replay...
But the Action Replay doesn't work for the DSi, the one for DSi is rumored to come in September
Mads Hak died in 1555.
Yvonne Hak was born in 1986.
Pavel Hak was born in 1962.
Give me hak sow i can hak to
Hak Pak was born in 1915, in Korea.
Sohn Hak-kyu was born in 1947.
Hak-dong Station was created in 2000.
Kim Hak-kyun was born in 1971.
Hak Ji Sa was created in 1992.
Paek Hak-rim died in 2006.
Paek Hak-rim was born in 1918.
Kim Jeong-hak died in 2006.