the Mii is your online character fo games like WiiSports. you create them in the Mii channel on the Wii. the online is gonna be used for most multiplayer games (i think). im just excited about SSBB being online! as for the memory, the Wii has 512K of memory for gamesaves and downloads. it also has an SD (Scan Disc, the cards that are commonly used in digital camerias) card slot for additional storage. hope that helps!