"Cocoa Worlds of Science" review - An article describing Cocoa's 1997 contest and gives some good tips for aspiring Cocoa developers.
Apple's Cocoa - Cocoa FAQ, examples with quicktime, and links.
Children's Online Cocoa Games - Some games created by kids, plus downloads of the official Cocoa stuff.
MIT Media Lab: Programming by Example - Good resource, has whole text of the book: Watch What I Do.
Project Cocoa - An on going attempt to keep the Cocoa community alive.
Stagecast Software - Visual programming environment based on Cocoa. Runs in Java.