I just found out streams can deliver a lot of different kinds of content over the server without much hassle. More info: http://ejohn.org/blog/node-js-stream-playground/

httpServerPipe

var fs   = require('fs');
    util = require('util');

/**
 * Exercise 1
 * Make an HTTP server that serves files. The file path is provided in the URL like this: http://localhost:4000/path/to/my
 */

require('http').createServer(function(req, res) {
    var file = '.' + req.url;
    console.log(file);
    fs.exists(file, function(exists) {
        if (exists) {
            fs.stat(file, function(err, stat) {
                var rs;

                if (err) { throw err; }

                if (stat.isDirectory()) {
                    res.writeHead(403);
                    res.end('Forbidden');
                } else {
                    rs = fs.createReadStream(file);
                    res.writeHead(200);
                    rs.pipe(res);
                }
            });
        } else {
            res.writeHead(404);
            res.end('Not found');
        }
    })
}).listen(4000);