You can get around Firefox fast without taking your fingers off the keys, but mouse fans will be happy to know there are a whole lot of ways you can get things done in the 'fox by dragging and dropping text and images as well. For example, you can drag and drop:
a URL (hyperlinked or not) onto an empty area on the tab bar to immediately have that URL opened in a new background tab.
an image onto the address bar to immediately have that image open in the current tab. CyberNet News runs down more more drag and drop goodness in Firefox; hit the link to see the rest.
Helpful Tip: Drag & Drop Text/URL's in Firefox [CyberNet News]