Simply capture web-page screenshot with PhantomJS

screenshot.js

#!/usr/bin/env phantom
var webpage = require("webpage"),
    system = require("system");

var args = system.args;
if (args.length < 3) {
    system.stderr.writeLine("usage: " + args[0] + " <URL> <Filename.png> [delay] [viewWidth] [viewHeight]");
    phantom.exit();
}

var url        = args[1];
var filename   = args[2];
var delay      = args[3] || 3000;
var viewWidth  = args[4] || 1280;
var viewHeight = args[5] || 960; 

var page = webpage.create();
page.viewportSize = {
    width: viewWidth,
    height: viewHeight
};
page.open(url, function() {
    setTimeout(function() {
        page.render(filename);
        phantom.exit();
    }, delay);
});