Snapshot a page with slimer.js

slimer.js

var webpage = require('webpage').create();
webpage
  .open('http://localhost:8000')
  .then(function() {
    // store a screenshot of the page
    webpage.viewportSize = { width:650, height:320 };
    webpage.render('/home/bdahl/projects/gecko/page.png',
                   { onlyViewport:true });
    slimer.exit();
  });