Hey I'm new here. (Just got my Wii 12/17 so I've been looking for homebrew sites.)
But the past couple of days I wrote an ASP "App" that will use IIS (Internet Information Servcies, web server for Windows) to stream mp3's and convert movies into FLV files for streaming.
This is really a more of "Proof of Concept". But feel free to check it out. (This should also work on any ASP server, with alttile techy know how.)
Besure to read the "Readme.txt" files, it should explain how to install and setup IIS on an XP Pro computer.