Opera tries to figure out the natural "next link" for a page, even if it doesn't have a formal one defined (Opera and iCab are the only browsers I've seen that actually implement a menu for navigational meta links, which are seldom used). You need not even touch the mouse: spacebar pages down and then goes to the next link, which also seems to be automatically cached ahead (very nice). This is useful with search engines, for example, where you can use it to page through the results. There is also a "rewind" button that acts sort of like Safari's "SnapBack" button.