Pineapple Surprise! is a PHP implementation for the Wi-Fi Pineapple or "Jasager". Used in conjunction with dnsspoof it will serve a "surprise" to any clients connected to the device when they make an HTTP request.
For more information on the Pineapple, check out "The beginners guide to breaking website security with nothing more than a Pineapple": http://www.troyhunt.com/2013/04/the-beginners-guide-to-breaking-website.html