gistfile1.js

Array.prototype.unique = function() {
    var uniqueKeys = {};

    var items = this.length;
    while( items ) {
        uniqueKeys[this[--items]] = true;
    }

    var uniqueArray = [];
    for( var key in uniqueKeys ) {
        uniqueArray.push( key );
    }

    return uniqueArray;
}