Firefox is the ultimate browser for your customizing pleasure. You can change themes, add search engines, and install various extensions to improve its functionality and look to meet your needs. Here are some of my favorite Firefox Add-ons.
StumbleUpon is a social bookmarking extension that makes surfing the web fun and exciting again. When setting up your account you select from a list of things that interest you. Then all you have to do is click on the “Stumble” button and it takes you to sites that contain those things you like.