FYI, a friend of mine just pointed out that Darren put together a great video on how to deploy this attack using DNSSpoof. Thanks Darren, I hadn't seen this until now. :-)
Also, I put together a presentation on this topic which shows a screenshot of the form processor (the only somewhat difficult piece of this attack). This will allow you to re-create this and similar popular captive portals. The updated form processor also allows for pass-through of users once they 'authenticate'. I cannot post the updated code for obvious reasons, but you should be able to re-create it using Darren's video and my slides...
http://www.slideshare.net/heinzarelli/wifi-hotspot-attacks