Here is a nifty feature of having the Web Browser on your Wii that some of you might not know:
Go on your PC and download WinAmp 5.5 - and install winamp remote as well. Set it up so Winamp remote can access the folder on you PC where your music and/or videos are stored.
Then go to the winamp remote webpage from your wii and you can play the audio files (or video files) stored on your computer straight through your Wii!
Only downside is if you have a lot of DRM protected audio or video then you can't play them unless you strip the DRM off first. No problem playing other stuff though.