We've seen a handful of wireless bio-monitors taking shape in various forms over the last few months. But from we can tell, the BPGuardian from SunTech Medical and Empirical Technologies is the first small-scale wrist-worn monitor that keeps track of blood pressure, one heartbeat at a time. The data collected from the device is then sent via Bluetooth to a PDA or computer -- so if your blood pressure needs constant monitoring, you should probably consider checking this out. Even the military is interested in using the 'Guardian to learn about how soldiers can better overcome combat stress. We've got no idea how much this gadget will set you back, but if it ends up saving your life or helping your doctor improve your health, it's probably worth every penny.