A scrolling map of San Francisco pans continuously leftward, with a tile-based image rendered to a Canvas element. The example uses the `pixymaps` library to manage view coordinates and tile loading, while the D3.js timer drives a subtle acceleration that increases scroll speed. Map tiles are loaded from CloudMade, and the view is projected using `d3.geo.mercator` to center the map. The animation updates the canvas by panning the view and re-rendering the image each frame.