Compressing iTunes Library Like most of you I have a very large iTunes Library with a lot of video content; I was wondering if it is possible to save the video content in compressed form(since space is always an issue) but still keep your contents available in you iTunes Library; preferably iTunes does the archiving &amp; unarchiving automatically.

I know that having to unarchive a movie before watching it must sound a bit tedious but considering that a lot of time might pass between watches I think it is worth it.
The problem with files like MP3 or AAC is that they are actually already compressed.  The MP3 and AAC codecs have advanced compression schemes designed specifically for audio.  You'll find that doing additional layers of compression on these types of files will make very little difference in disk space usage and will probably not make it worth your trouble.

EDIT: Sorry I got confused.  The OP asked about video, but the same applies.  Video content is compressed and you'll get very little benefit from further compression.  It's really not worth messing with.