ssh
Need More Sharing From Home Sharing?
If you find the new iTunes 9 feature "Home Sharing" a bit lacking then you may be interested in this remote management compendium I put together a few months ago. If you're ready to really get your hands dirty with things like ssh, rsync, launchd, and more, you can design a system to copy/backup/add any iTunes files to other iTunes apps on your network in the background.
DIY: Remote Management Assortment, Part 5
I've added a Part 5 to DIY: Remote Management Assortment that describes how to create and delete playlists on a remote user's iTunes with ssh and osascript. If you haven't been following along in this series of projects, you may want to start at the beginning; this newest addition builds on routines and concepts from earlier in the series.