Firefox

When you open a new tab, you can instantly start typing and press ENTER which sends your query to the search engine.

However once that's done, there's no easy way to edit the query directly from the URL bar. The URL bar will contain, well, the URL and not the original query anymore.

Is there a way to edit the search query w/o using the search engine's web page or retyping the whole query again? In other words, is there a way to tell Firefox to show me the previous query in the URL bar instead of showing the URL?

I'd like to try to send as many queries as possible to Google directly from Firefox rather than using Google's webpage (more $$$ for Firefox.)