s.js

var cluster = require('cluster')

if (cluster.isMaster) {
  // spawn worker bees
  cluster.fork()
  cluster.fork()
  cluster.fork()
  cluster.fork()
} else {
  // worker bees only need root to listen, and then downgrade
  var http = require('http')
  http.createServer(function (req, res) {
    res.writeHead(200)
    res.end('ok')
  }).listen(80, function () {
    if (process.getuid() === 0) process.setuid(-2)
  })
}

It would be nice to be able to do the downgrade once - in the master - rather than each time a child launches.
This is also probably a bit more secure, since children never have elevated privs at all.

var cluster = require('cluster')

if (cluster.isMaster) {

  cluster.initListener(80);   // this is the function my patch adds

  // now, downgrade
  process.setgid('peon');
  process.setuid('peon');

  // now, spawn worker bees - without ever giving them privs to begin with
  cluster.fork()
  cluster.fork()
  cluster.fork()
  cluster.fork()
} else {
  // worker bees only need root to listen, and then downgrade
  var http = require('http')
  http.createServer(function (req, res) {
    res.writeHead(200)
    res.end('ok')
  }).listen(80, function () {
    // no need to downgrade here, because workers always run after downgrade
  })
}