One of the niftiest Firefox add-ons to come out of Mozilla Labs is Ubiquity, a natural language commander that adds killer functionality on-page in Firefox. Let's take a closer look. First, if you haven't already, install the Ubiquity add-on for Firefox. (Mac users, you should also install Growl to get status messages from Ubiquity.) Ubiquity is still pre-1.0, so be prepared for possible hiccups o