Playing JS Golf with PubSub. 171 bytes gzipped

gistfile1.js

function ps(d){c={};d.pub=function(a,b){for(var i=c[a].length;i;)c[a][--i].apply(this,b)};d.sub=function(a,b){c[a]?c[a].push(b):c[a]=[b]};d.unsub=function(a,b){c[a]=(c[a]||[]).filter(function(i){return i!==b})}}

ps() adds pub/sub/unsub methods to any object.
For instance: ps(window);
After this, window.sub(channel, function) sets function to be called whenever data is published to channel,
window.pub(channel, values) applies the array values of values as the arguments of each callback on channel,
and window.unsub(channel, function) removes function from the list of methods subscribed to channel.