I'm addicted to Firefox's keyboard shortcuts. You can open a new window, enter the address of a website and close the window without moving your hands out of QWERTY position.  

Use Firefox smart keywords to make it easier to use your favorite search engines to find what you need faster.  Takes about a minute to add a web site to your Smart Keywords list, and then you have an easy way to search websites right from the browser Location bar (where you usually have to type the whole web address).