The Xperia Arc is one the best handsets we've seen from Sony Ericsson, but US consumers have had to sit by and watch as the thing popped up in other markets around the world -- until now, that is. The unlocked quad-band 3G handset just hit Sony's store. The Gingerbread-packing smartphone has a 4.2-inch Reality Display, 512MB of RAM, an 8 megapixel camera, and will start shipping tomorrow. The Xperia Arc will run you $600 -- that's the price you pay for contractual freedom.