Mii Channel… DS?
Nintendo guru Shigeru Miyamoto revealed towards the end of GDC that they had been toying with Mii creation for over two decades without much success. It wasn't until the Wii was released that the avatar program found a suitable home. A recent developers' chat with some of the Mii Channel programmers revealed early screenshots of the Mii editor when it was a Nintendo DS program! All of the same functions appear to be in this early version, though the graphics are still in their rough dev stage.
Having a portable Mii isn't a bad idea!