An article in today's Times points out a surprising (to me) security vulnerability in smartphone and other GPS-equipped cameras: They mark images with invisible but easily readable* "geotags" pinpointing where (and when) the photo was taken. Take a picture with an iPhone or a Droid inside your house, post it on the Web, and you've just shared your home address with the Internet. Combine that picture with a blog post about your vacation plans, and, well... you didn't really need that TV or ste...