What annoys me sometimes, yeah I'm kinda shortminded, is that when you want to browse through a certain site, that you explicity have to go to the location of the "next" button or click on a number on the button of the page, like 1 2 3 4 5 (where as every number is a different page) But what if you are somewhere in the middle of a long scrollable page and you don't want to hit the home or end button (to respectively go back to the top and bottom of the page) and continue by clicking on a button that navigates you to the next page. Wouldn't it be easy if there's some kinda of alternative "forward" button, not the ones used in the browser that navigates you back to the page where you were, in case you hit the "go back on page" button. But some kind of button that checks the URL on a variable, for example the variable, page or any other often used variable that indicates a pagenumber. Making some short of hierachy of variables (library) to check and see if that URL really exists (I don't know how long this would actually take though), and if so, navigate to that certain URL.
For example: My url: http://www.multitouch.nl/?p=48
Look for the variable "page" in the url, which doesn't exsist.
Look for the variable "p" (hierachy), because it's a commonly used var for indicating pages.
Okay it finds the "p". In this case the p=48.
Then do a calculation of 48 - 1 = 47
And applying the new p var to next button.
Maybe this is something that is already been done, I don't know. It just came up in my head. If there's some sort of firefox plugin like that, please let me know.
Another example:
Look for a number in a URL:
http://tweakers.net/nieuws/47594/
It finds 47594. Recalculate 47594 -1 = 47594 and it will get you the the next (in this case) an older news message) page.
I'm sure there are some hickups to this, but it's just a concept.