I'm one of those sad souls who's dying to pick up a Nintendo Wii, but never can find one in stock. For those of you lucky enough to have one you might like to check out Mii Transfer from Mike Cohen. Says Mike, "Mii Transfer is a tiny utility which lets you copy your Miis from your Wii Remote to your computer so you can share them on sites such as MiiPlaza.net and edit them using Mii Editor." Well as soon as find a Wii, at least I know my Mii will be well looked after.
Mii Transfer is open source and a free download from Mike's site.
Update: Unfortunately, this seems not to be working for people. It would perhaps be best to contact Mike Cohen directly.