Array shuffle method using Mike Bostock's Fisher-Yates Shuffle implementation. Original is here: http://bost.ocks.org/mike/shuffle/

array.shuffle.js

/**
 * Extends the primitive Array with a random sort function
 *
 * @returns {Array}
 */
;Array.prototype.shuffle = function() {

    var arr = this,
        m = arr.length,
        t,
        i;

    // While there remain elements to shuffle…
    while ( m ) {

        // Pick a remaining element…
        i = Math.floor( Math.random() * m-- );

        // And swap it with the current element.
        t = arr[ m ];
        arr[ m ] = arr[ i ];
        arr[ i ] = t;
    }

    return arr;

};