What's the smallest you thought a Bluetooth headset could go? If your answer was "pretty close to the size of Apple's iPhone Bluetooth Headset," think again: Argard's M10 ($149) is smaller. The size of a stack of watch batteries with a silicone-tipped earbud attached, M10 weighs 5 grams, measures 23mm by 22mm by 31.5mm, and features a battery with 3 hours of talk time -- the compromise you make for its size -- or 100 hours of standby time. Like many…
