While they may not have an particularly desirable impact on your image, wireless Bluetooth headsets are convenient, and their continually dwindling size gives us the hope that some day you could wear one without anyone noticing. But, smaller size equals smaller buttons, an issue Philips is looking to dodge entirely with its latest stereo Bluetooth headset, the Tapster. It relies on touch inputs, not moving ones (other than a wee power button), meaning you'll be able to administer a gentle stroke to adjust volume or a light tap to answer a ca