Something I like - Remove It Permanently

One of the great things about Firefox / Mozilla is the ability to install "add-ons" to it which enhance its functionality. They are cross-platform (so it doesn't matter if you're running Firefox on Windows or a Mac etc) and some of them are just brutally useful. For example, one of my favorites is called "Remove It Permanently" (RIP, get it?). It allows you to remove from sight any element of a web page that you deem unsightly or distracting (link above goes to where you can download the add-on).

For example, earlier I was viewing this excellent chart of an orange line intersecting a purple line on the website Pollster.com:

(click to enlarge)

The advert in the lower right was a bit distracting, with all the flashing and whatnot, so I decided to remove it. I right-clicked on it and a red frame appeared around the element to which it thought I was referring (it needs to make certain assumptions based on how the HTML of the page is constructed, but it rarely takes more than one or two tries to "point" it at the right thing):

I then selected "Remove It Permanently"...

... and the page instantly re-draws itself as if that portion of the HTML had never existed. Some web sites are unreadable without it, in my opinion.