There are some default shortcuts in the Firefox URL Bar:
^ to search for matches in your browsing history.* to search for matches in your bookmarks.+ to search for matches in pages you've tagged.% to search for matches in your currently open tabs.# to search for matches in page titles.$ to search for matches in web addresses (URLs).? to search for matches in suggestions.Additionally, you can create your own shortcuts. For example, if I write we mozilla in the URL bar, it opens a Wikipedia page, in english, for "mozilla".
To do so, create a bookmark by using:
http://en.wikipedia.org/wiki/%sweI have the following bookmarks in Firefox: