Awesome

XXSPubSub

Extra Extra Small publish/subscribe micro-framework in JavaScript

It's only 182 bytes of gzipped JavaScript and it works grate, read the documentation and try it yourself.

If your project use jQuery, use this version of XXSPubSub, is the smallest posible pubsub done with jQuery, it's only 111 bytes gzipped!

Also if you like CoffeeScript, a .coffee version is included