Display console.log output (useful on jsfiddle for instance)

console.js

function newLog(oldLog) {
  return function() {
    var args = Array.prototype.slice.call(arguments, 0);
    document.getElementById('console-log').innerText += args.join(" ") + "\n";
    oldLog.apply(this, args)
  }
}
console.log = newLog(console.log)
console.error = newLog(console.error)

markup.html

<p id="console-log" style="font-family: monospace;"></p>

Example: http://jsfiddle.net/wdgfnn0h/4/