LG's GD910, which went on sale in Europe last year, kicked off the trend. We're looking forward to seeing this prime video-chatting, text-messaging watch stateside at this month's Consumer Electronics Show, along with new models from Kempler & Strauss and others. All of them let you converse through built-in speaker-phones, à la Tracy, or maintain privacy by beaming sound to a Bluetooth headset. Fitting such versatility into thin cases required years of engineering to squeeze together parts that are usually separated. (Kempler & Strauss, for example, overhauled a standard cellphone circuit board several times to keep the cellular and Bluetooth radios from interfering with each other.) Look for upcoming models to pack even more features, like GPS and Web access, in even smaller packages.