Javascript: Remove duplicate values from an array

I did a Google search for different methods of removing duplicate values from an array, and I found a bunch of crappy algorithms that all returned a new array, rather than paring down the original array. So I wrote this, which wouldn't work on identical complex objects, but works great for primitive data types and objects stored by reference.

function removeDuplicates(arr) {
  arr.sort();
  var i = arr.length - 1;
  while (i > 0) {
    if (arr[i] === arr[i - 1]) arr.splice(i, 1);
    i--;
  }
}