Ever wonder what the offspring of an after-party Twitter and Digg copulation might look like? No, well aren't you pure and normal. Regardless, we fantasize about it all the time but never expected this iPhone payment dongle to be first from the litter. Square is Jack Dorsey's (Twitter co-founder) new startup that now has Kevin Rose (Digg founder) on board as an investor and YouTube pitch man for the prototype payment device that plugs directly into the iPhone's headphone jack. We've covered Square before but this is the first video that clearly demonstrates the full capability of the credit card swipe system on a live device. A compelling proposition for receiving cashless payments if you're a small business owner looking to exploit irresponsible credit card debt or just the average Joe hocking goods at a garage sale, farmers market, or Craigslist. Assuming of course, Square's cut of the transaction isn't too egregious. Demo after the break.