UrlBarExt

It's a firefox extension that allows you, with a single click, to TinyURL your current position, search within a website, and go UP a directory level in a website! I especially like the TinyURL feature, as it automatically copies it to your clipboard, ready for pasting, in a single click. One problem is that I don't think there are any keyboard shortcuts involved, which is sort of a bummer. Nonetheless, a very, very convenient add-on.