This post was published more than a few years ago (on 2006-03-15) and may contain inaccurate technical information, outmoded thoughts, or cringe takes. Proceed at your own risk.
Via Gizmodo:
The Guinness Surger is a electrical device with a small metal plate on it; you pour a little water onto the plate, put a pint of the special Guinness Draught Surger Beer in place and then turn the power on, sending ultrasonic pulses up through the beer to create the creamy head we all know and love. If that sounds incredible, you really need to watch the video and see it in action.