May 9, 2001: The idea of hobo signs suggests a location-aware wireless application: I'm sure someone's already doing this, but I'd love to see location-based public message boards (e.g. restaurant reviews or "to catch a cab, better go down the block"). Because the thing that's so cool about hobo signs is that it's user-created wayfinding/metadata. It's a public layering of information space on physical space.