If your favorite web site has search capabilities, you can bring them to your search toolbar for easier, faster access. OpenSearchFox, is a simple unobtrusive extension for Firefox that makes an OpenSearch plugin from any search form.
For example, to add Mozilla Links as a search engine, once installed, right click in the search box in the right sidebar, and select Add OpenSearch plugin. It will ask for confirmation on the search engine name, description and the default icon. I am not sure why it didn’t find Mozilla Links’s favicon but it added a default blue magnifier icon. Now I can search Mozilla Links directly within Firefox. Nice!
It does have a couple of weaknesses, though. Besides not finding the favicon (but it did with Mozilla Add-ons) which can be an inconvenience, it adds the option to add a certain form as a search engine to every text box, but I guess it is a limitation that would require lots of effort to try to guess whether a text box receives search terms or any other kind of data. In fact, Firefox’s own Add a Keyword for This Search… is present in all text boxes.
Try it and you will find this extension is as close to magic as an extension can get.