index.js

var casper = require('casper').create({
  viewportSize: { width: 1024, height: 768 }
});

var i = 0;
var interval;

function takePictures() {
  interval = setInterval(function(){
    var n = ((i < 10) ? '0':'') + i;
    casper.capture('image-' + (n) + '.jpg', {
      top: 0,
      left: 0,
      width: 1024,
      height: 768
    });
    i++;
  }, 1000/8);
}

casper.start('http://casperjs.org/', function() {
  takePictures();
  casper.click('.nav li a');
});

casper.waitForUrl(/latest/, function(){
  clearInterval(interval);
});

casper.run();

Makefile

run:
	casperjs index.js && convert *.jpg video.mpeg && gify video.mpeg out.gif && rm *.jpg video.mpeg