gistfile1.js

// tweet-sized, and does (approximately) the same thing
var t=document.all,l=t.length,w='-webkit-trans';while(l--)t[l].style.cssText+=w+'ition:all,20s;'+w+'form:rotate('+Math.random()+'rad)'

w="-webkit-trans";i=0;while(e=document.querySelectorAll("div")[i++])e.style.cssText+=w+"ition:20s;"+w+"form:rotate("+i/10+"rad)"

109: like @joside's but with * instead of div

s='-webkit-trans';document.styleSheets[1].addRule('*',s+'ition:20s;'+s+'form:rotate('+Math.random()+'rad)')

Edit:

Not sure where the 20s came from but 9s looks just as good:

s='-webkit-trans';document.styleSheets[1].addRule('*',s+'ition:9s;'+s+'form:rotate('+Math.random()+'rad)')

I think @joside has won this game.

@marcheiligers : what if there is actually not any document.styleSheets ?

Should be able to get it to work in Opera with '-o-trans', which would shave 5 chars but I can't get it to work :-(. Means you loose 1% of browser market share though.

[].map.call(document.all,function(e,s){s='-webkit-trans';e.style.cssText+=s+'ition:20s;'+s+'form:rotate('+Math.random()+'rad)'})

Array.prototype.slice.call(document.all).forEach(function(e,s){s='-webkit-trans';e.style.cssText+=s+'ition:20s;'+s+'form:rotate('+Math.random()+'rad)'})