Substantially cleaner in design than last year's stereo Bluetooth ety8, Etymotic's new EtyBLU ($129) is a modular monaural Bluetooth earpiece designed to let iPhone users take and make phone calls without a wired headset. With Bluetooth 2.1 (and backwards) support, EtyBLU features dual microphones -- one in the base, one in the detachable, user-adjustable boom -- and a foam windscreen for the boom mic, plus an in-canal, silicone-tipped earpiece that…