Careful what photos you tweet--and where you were when you snapped the shot. There's another site designed to warn you against the hazards of over-sharing. This time it's not related to active location-sharing, but instead accidental. The meta-data stored in your photos may be giving away where you live.
Have you ever noticed how little sense the placement of zip codes make? Sequential zones are an entire city apart. Sometimes there are even zip codes wholly contained within other zip codes. It takes a visual zip code map to make sense of it. Huge.info has just such a map using an interactive Google Map and custom overlay images.