The Withings Baby Monitor is finally available in the US, and it's one expensive iPhone accessory. First teased in January, the gadget is on sale for US$299. The corresponding iPhone app is free. What does it do for three hundred bucks? It monitors the humidity in Junior's room, lets you know when he's awake and even has night-vision mode. Plus, this goes without saying, it's a huge leap beyond the audio-only set I use