June 18, 2007: It occurred to me the other day that Scott McCloud's point about the web's infinite canvas applies (and is vastly more important) to annotating physical space. Any given physical location needs both multiple categories of information (e.g. basic information, reviews, history, etc.) and also infinite instances of each. And it's going to get real messy real fast, given both the variety of data (where's the nearest bathroom vs. Mark Twain slept here vs. I love this place vs. danger: asbestos!) and the imprecision inherent in this kind of layering (did Mark Twain sleep here or over here or maybe right there?). I don't see any way to do that other than to open it up and let the world have at it.