While Aliph was announcing its luxurious Jawbone Icon Bluetooth headsets earlier today, we've been playing with one of its six designs -- The Ace -- at our cozy London pad. Being the smallest and lightest Jawbone ever, the Icon's obviously challenging the likes of Jabra Stone with attempts to outperform in noise elimination, battery life, ergonomics and ease of operation. On paper, the Icon already wins on battery life and price, although the Stone has a charging dock good for six extra hours. What really matters, though, is the usability -- something the Stone had