Quick searches and keywords 
Quick Searches allow you to define custom search keywords for entering in the Location Bar. After setup, just type your search keyword before your search terms. A wiki of popular quick searches is maintained here. The steps needed to make a new Quick Search are outlined below:
- Go to a web page that contains a search box.
- Right click in the search entry box.
- Select "Add a Keyword for this Search".
- Give your quick search a keyword. For example, a Wikipedia search could be w. Obviously, shorter keywords are more efficient than longer ones, such as wikipedia.
An alternative method for older versions of Firefox or locations without search boxes is to:
- Go to a webpage that contains a search box.
- Search for something. In this case, oddball will be the search word.
- Note the term in the URL, and replace it with %s. For example, searching on the Google search engine gives us the URL:
- Using our example, the new address would be:
- Copy the modified URL from the location bar.
- Go to Bookmarks → Manage Bookmarks → New Bookmark.
- Paste your modified URL in the Location box.
- Give your quick search a name, e.g. Google Quick Search.
- Give your quick search a keyword. Note: This can be one character or more. For example, a Google search could be g.
To use your new quick search all you need to do is type keyword your search term in the address bar; for example, to search for the information regarding the history of Wikipedia in Google, you would type, g history of wikipedia. You can also bookmark advanced searches using the same technique. Just try a search and replace your search term with %s. Simple!
This functionality doesn't have to be limited to web searches; it can be used to quickly go to pages that have a certain structure. For example, one way to get more out of Wikipedia would be to create a bookmark to http://en.wikipedia.org/wiki/%s with keyword w. Getting to Wikipedia articles now only requires typing in w article title.
Another example is currency conversions. To easily convert from US dollars to Euro, one could create a bookmark to http://www.xe.com/ucc/convert.cgi?From=USD&To=EUR&Amount=%s and give it the keyword $. To convert a given amount (say $50), all one has to do now is enter $ 50 into the address bar (note the space, it's very important).
Once you start thinking about them, keywords can become quite useful.
You can also use the SmartSearch extension to do all your quick searches from the context menu, by highlighting a word on a page, right-clicking it and search using any of your quick searches.
Find Toolbar 
A new and innovative feature is the Find Toolbar. The Find Toolbar is used for searching for text within a page without being too obtrusive. When activated by pressing Ctrl+F, the Find Toolbar appears on the bottom of the Firefox browser ready to search the current web page. The Find Toolbar using incremental searching which means that it will look up your search term simultaneously as you type it. This is more robust than traditional find as finding is done immediately when typing starts. The Find Toolbar has the ability to find the next or previous result and select it, highlight all the matched results and match case. Firefox will search down until reaching the end of the document and "wraparound" to the beginning of the page. If there are no results matching your terms, Firefox will 'beep' to inform you of this. (If you want to disable this 'beep' go to about:config and change the value accessibility.typeaheadfind.enablesound to false.) When you are done searching, simply press the Esc key and the Find Toolbar will hide.
Find As You Type 
A very useful feature is Find As You Type, which lets you use the functionality of the Find Toolbar without having to open or close it with Ctrl+F or Cmd+F.
By default, Find As You Type will only begin after pressing the / key. Alternatively, to only search links, press the ' key (apostrophe). However, it is possible to have Find As You Type work without needing an additional key press. To do so, go to Tools → Options → Advanced → General and check "Begin finding when you begin typing".
From now on, when searching about some topic on a website, just start typing into the body of the page. You will instantly go to the first instance of the sequence of letters as you type. The Find Toolbar will temporarily appear at the bottom of the page, allowing you to highlight all the places the term occurs, or jump to the next one. More Find Toolbar shortcuts can be found in the Keyboard shortcuts section, and a complete description here.
A useful tip to navigate around a web page is to use find as you type. You simply push the ' key (apostrophe) and begin typing the text of the link you wish to follow. Once Firefox highlights that link (whether you've only typed a few letters or the entire word), you hit the Enter key and Firefox will begin loading that page. For example, if on this same page, you quickly want to go to the Table of Contents. Notice that the link for the table of contents is << To Contents. Press the apostrophe key to activate the Find Toolbar for searching for links and then type "to". Firefox will then highlight part of the link. Pressing enter will take you to the Using Firefox Table of Contents. One thing to note is that the apostrophe key does not necessarily have to be used for this tip to work; just using Find As You Type can accomplish the same thing, but since it searches all text, whether it's a link or not, it may not be as quick as beginning your search with the apostrophe key.