There's a number of keyboard shortcuts in the Firefox browser, I already knew (and used) a bunch of them. While looking for something else, I found this nice, convenient page describing all the shortcuts (for all platforms and versions): http://support.mozilla.com/en-US/kb/Keyboard+shortcuts

Glancing through this, I actually discovered a few that I didn't know about, like, -j (or k) will move focus to the search text area, and highlights the old text. Or that I can have Firefox "autocomplete" a .com address by hitting - while typing a URL.