The Nintendo Wii is a great little game console, sure to occupy you for countless hours either playing Wii Sports or Twilight Princess. Going away from the "games only" approach of previous Nintendo consoles, the Wii is also a quite capable photo viewer. But what is most interesting, at least for this website, is Wii's video playback capabilities. With a little bit of help, you too can play back your video files on the Wii.
Nintendo Wii supports playback of AVI and MOV files using the MJPEG codec, although on my version of the Nintendo Wii manual (Australian), only MOV files is said to be supported (meanwhile, AVI is listed as the only supported format on the Nintendo Europe website - let's just assume both formats will work). The audio portion of the movie seems to only support PCM uncompressed audio, which is a shame. MJPEG is not the most efficient video codec around, and at 2048kbps (about 15 MB per second of video), you will only get marginally acceptable quality for DVD resolution video.
In other words, the Nintendo Wii is not best suited for video playback, but with a 2GB SD card, you might be able to fit about an hour of DVD quality video onto the memory card.
There is only 3 things that you need. Of course you need a Nintendo Wii, a SD memory card that is at least 1GB, and
Wii Video 9.
You can go
here for a step by step guide on how to use your Wii console to watch your video files.