If you find that finding and hitting the next page button while searching the web is a chore, PageZipper is for you. It loads the next page as you reach the bottom of the current one.
Installation doesn't automatically activate PageZipper. You need to go into the View-Toolbars-Customize menu and drag the PageZipper icon into your Firefox toolbar. Once done, in many pages when you scroll to the bottom, the next page will automatically load beneath it.
For searches, like Google, PageZipper is fantastic. It also works on Flickr, so you can get lost in an almost endless page of photos. PageZipper works by identifying the "next" link, so if a page names the link another way, it probably won't work. This means most Blogger blogs won't auto load.
Despite some limitations, PageZipper is worth installing just for making Google searches faster.