No mic is a big problem. I've tried that with a friend - he could hear me but could not speak and whole experience was pretty frustrating. We gave up after two test chambers. You don't need hifi quality mic, cheap 2$ mic will be enought. Or plug your headphones (that type you stick into your ear, like stock ipod headpones) into mic port, hold both earpices near you mouth a try record something. it will work, but this solution require some tweaking and quality will be very low