From Acertant Technologies:
TuneRanger connects iTunes-running computers over a network, allowing music, video, and playlists to be copied from one iTunes library to another seamlessly. TuneRanger even works across platforms letting iTunes on Windows communicate and synchronize with iTunes on Mac or any combination. TuneRanger offers true synchronization. It compares songs and videos on all computers and only moves what has changed. It even does this for playlists. Version 1.0.1 added compatibility with the new iTunes 8.
What's new in this version:
Version 1.0.1 added compatibility with the new iTunes 8.