I had previously posted on this topic when iTunes was released but in a different forum ( http://www.hydrogenaudio.org/forums/index....roconfig&st=25& ). Raising it again here in the hopes that someone who can program might be interested in the idea enough to implement it:

A plugin to share (stream) files via zeroconfig + daap, with optional real-time conversion to a target format. For example, this would permit any foobar program to act as a server for other foobars or for iTunes and TiVo (assuming in the latter two cases that the plugin converted source audio on-the-fly to MP3 or AAC).

A greater explanation follows: I like the user interface of iTunes and its compatibility with the iPod. But my music collection is in FLAC lossless audio format, which is incompatible with iTunes. For this reason, I can't use iTunes to listen to or share my FLAC songs unless I first decode to WAV or transcode to MP3. Doing so incurs time, effort and hard drive space. And every time I change my FLAC songs (i.e. retag them), I need to mirror that change in the WAV/MP3 file. Meanwhile, foobar has wonderful codec support, diskwriter and tagging capabilities, and small size but a minimal interface and no ipod support.

There are a variety of open-source projects which come close to this, many providing daap server or client capabilities, but none offering transcoding that I am aware of.: for example: http://www.deleet.de/projekte/daap/ (upon which most daap code is based)
http://daap.sf.net/
http://projects.tynsoe.org/en/musicpublisher/index.php
http://www.cowpimp.com/

With this proposed plugin, foobar could both serve and receive shared streams. Perhaps any available stream source would automatically appear under the Playlist menu in foobar. And foobar would show all my FLAC files as if they were MP4 files in iTunes. Options might also include creating virtual playlists from the directory structure or artist/album/genre tags in foobar.