The Memory Pak peripheral for the N64 plugs into the N64 controller, and can be alternated with the Rumble Pak. It is required to save ghost data in Mario Kart 64. Since the Virtual Console does not support the Memory Pak, the VC release of MK64 cannot save ghost data.
The GameCube also requires memory cards for creating game saves. These cards can be plugged into slots situated atop the Wii (where the GameCube controllers are plugged into). Using the Wii data management menu, games can be transfered from one memory card to another, or even erased.