Node script to grab tiles from http://xkcd.com/980/huge/

money_tiles.js

var http = require('http'),
    fs = require('fs'),
    output = './money_tiles7/',

    // Tokens and ranges for the 1:1 detail level
    zoom = 0,
    xmin = 0,
    xmax = 48,
    ymin = 0,
    ymax = 32,
    x = 0,
    y = 0,
    i = 0;

function pad (str, length) {
    var filler = '0';
    // Yuck.
    return new Array(length - (String(str).length - 1)).join(filler) + str;
}

function next () {
    var filename = 'tile_' + pad(zoom, 3) + '_' + pad(x, 3) + '_' + pad(y, 3) + '.png',
        options = {
            host: 'imgs.xkcd.com',
            path: '/money_tiles7/' + filename,
            port: 80
        };

    http.get(options, function (res) {
        var imagedata = '';
        res.setEncoding('binary')
        res.on('data', function (chunk) {
            imagedata += chunk;
        });
        res.on('end', function () {
            // Favor row-biased linear sequence naming. Join tiles via ImageMagick's montage binary
            // montage -mode concatenate -tile 49x tile_*.png joined.png
            fs.writeFile(output + 'tile_' + pad(i++, 4) + '.png', imagedata, 'binary', function(err){
                if (err) throw err;

                var clampx = x === xmax,
                    clampy = y === ymax;

                if (clampx && clampy) {
                    console.log('Done');
                    return;
                }

                if (clampx) {
                    x = xmin;
                    y = clampy ? ymin : y + 1;
                } else {
                    x++;
                }

                next();
            });
        });
    });
}

next();