Download a bunch of files in parallel. Depends on `npm install request`

download.js

var fs = require('fs'),
	request = require('request');

var download = function(uri, filename, callback){
	request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
}

var urls = JSON.parse(fs.readFileSync('./urls.json'))

for (var i=0; i<25; i++) {
	next()
}

function next() {
	if (!urls.length) {
		console.log("DONE!", urls.length, 'files.')
		return
	}
	console.log("Remaining:", urls.length)
	var url = urls.pop()
	var filename = 'files/'+url.split('/').pop()
	if (fs.existsSync(filename)) {
		console.log("Already downloaded:", filename)
		next()
		return
	}
	console.log("Downloading:", filename, url)
	download(url, filename, function(err) {
		if (err) {
			console.log("ERROR", err)
			process.exit(1)
			return
		}
		console.log("Done:", url)
		next()
	})
}