http://www.hackaday.com/2008/06/06/wii-dual-nand-flash-hack/
[ChipD] successfully installed two NAND flash chips into his Wii. He can keep the stock firmware on one and then flip a switch if he wants to boot using the other chip with a modified firmware. This hack is fairly straight forward. All it took was someone with steady hands to try it out. The new NAND chip is identical to the original and was salvaged from a flash drive. The chips were soldered as a stack except for the chip enable pin. The chip enable from each chip is attached to a small switch to toggle between which is active. You could use a TSOP socket to swap the different chips, but it wouldn't fit inside the Wii case. This little switch could be hidden easily next to the GameCube ports.
http://hackmii.com/2008/06/dual-nand-flash-hack/
[ChipD] successfully installed two NAND flash chips into his Wii. He can keep the stock firmware on one and then flip a switch if he wants to boot using the other chip with a modified firmware. This hack is fairly straight forward. All it took was someone with steady hands to try it out. The new NAND chip is identical to the original and was salvaged from a flash drive. The chips were soldered as a stack except for the chip enable pin. The chip enable from each chip is attached to a small switch to toggle between which is active. You could use a TSOP socket to swap the different chips, but it wouldn't fit inside the Wii case. This little switch could be hidden easily next to the GameCube ports.
http://hackmii.com/2008/06/dual-nand-flash-hack/