Mozilla FireFox has a few of the neatest extensions for a web browser.
My favorites are GoUp (with a press of Alt-UpArrow, it cuts the last segment of the URL and goes to the parent directory. www.livejournal.com/~yggdrasil_/friends will turn into www.livejournal.com/~yggdrasil_) and MouseGestures – hold down the mouse button and make a sharp jab to the left to go to the previous page. A thrust upwards and it goes to my homepage. A slash down – opens a new window. All this is customizable, and lets me do a whole lot of things with only my mouse hand. Once one gets used to it, it seems very, very convenient.