I’ve just installed the latest release of Firefox and am writing this from FF4. Everything works so fluidly and calmly. Lately I’ve been using Google Chrome for it’s speed but have been eagerly awaiting to use Mozilla’s perfect browser. One of my favorite features is the Paste & Go. It also have a much smaller menu and so forth, seems compacted but in a good way. Here’s a great article about how to install it in the latest Ubuntu releases http://www.webupd8.org/2011/03/install-firefox-4-in-ubuntu-1004-1010.html. If you haven’t updated yet, do so!