Ian Grant, Lecturer in Digital Art at Thames Valley University, has posted a couple of very innovative and interesting Quartz Composer related projects on his website:

• Quartz Composer and the Nintendo Wii Remote - QCWii a demo application (with source) making use of the open source "Darwiin-Remote" framework and a Nintendo Wii controller.
• Digital Puppetry Project Using Quartz Composer - involves chroma keying and other elaborate techniques.
• Movie Time-line Thumbnail Viewer
• Tiger Reflections Patch Version 2 - Can be turned into a Final Cut Pro plugin using FxFactory.
• Iris Transition
• Aqua Style Circle

Very cool stuff!