furf

// 1: how could you rewrite the following to make it shorter?
if (foo) {
  bar.doSomething(el);
} else {
  bar.doSomethingElse(el);
}

furf

// find out what prefix this browser supports.

// usage: gimmePrefix('transform') // 'WebkitTransform'
//        returns false if unsupported.

function gimmePrefix(prop){
  var prefixes = ['Moz','Khtml','Webkit','O','ms'],
      elem     = document.createElement('div'),
      upper    = prop.charAt(0).toUpperCase() + prop.slice(1);
      

furf

// pure JS
function shuffle(array) {
  return array.sort(function(){ 
    return .5 - Math.random(); 
  });
}

// with Prototype.js you can do
function shuffle(array){ 
  return array.sortBy(Math.random);

furf

// everyone's new favorite closure pattern:
(function(window,document,undefined){ ... })(this,this.document);

// minified:
(function(b,a,c){ ... })(this,this.document);

// which means all uses of window/document/undefined inside the closure 
// will be single-lettered, so big gains in minification.

// it also will speed up scope chain traversal a tiny tiny little bit.