Infinite Scrolling for Hacker News.
This extension provides an "infinite scrolling" behavior to news.ycombinator.com.
The next page of items is automatically loaded and appended to the current page. The HTML5 history API is used to save the latest page that's loaded and appended - so if you navigate away then come back it will return you to the latest items it loaded.
(In the screenshot, below the last item on the page there is a progress spinner with loading text which shows for a split-second before the new page items are appended).
Check my similar extensions for reddit and dribbble. View the source, add to it, etc. at github.com/dvoiss.