How does Stack Exchange generate load new pages so fast?
Using the network tab of Firebug for Firefox, you can see all HTTP requests being made. With this turned on you can see that clicking the next link fires off an HTTP request which grabs the next page of questions (i.e. it is not preloading all the questions with the initial page load). It's a small request, small response, and the server replies really quickly, which is why it happens almost instantaneously.