A Handy Tool for Making Scale Comparisons
Henry Grabar looks at MapFrappe, "Kevin Thompson's cartographic mixing engine." The site lets users outline any location on a Google Map and view that outline overlaid on a comparison map that retains the scale of the original shape.
"Once you get tired of outlining your own interests -- your walk to work in London, or Buckingham Palace on your block -- you can check out Drew's MapFrappe blog, which has hundreds of preset outlines to choose from." The site even lets you generate a permanent URL of the comparison to direct others to, or bookmark for later use.