One of the more obscure and, in my opinion, underutilized shortcuts in Firefox is something called a Quick Search. Now that Firefox ships with a search box in the upper right hand corner of the address bar the built-in Quick Search feature has taken a back seat. I remember when there were a set of Quick Search bookmarks pre-installed on new versions of Firefox, but that doesn't seem to be the case anymore. Quick Search shortcuts are simply specialized bookmarks that you edit to create custom searches. Here's how to create one:
1. For this example, head over to google.com.
2. Type in MYSEARCHTERM as the search term.
3. Create a bookmark of this search result page.
4. Go to Bookmarks > Organize Bookmarks.
5. Right-click on the bookmark just created and choose Properties.
6. In the Location string of the bookmark, find MYSEARCHTERM and replace it with %s (that's a percent sign and a lowercase s).
7. For Keyword, simply enter a lowercase letter g.
8. Click OK to save the bookmark.
9. To use the new Quick Search, open a new tab/window and type g searchterm into the address bar.
The real power in this comes from its customizability; any page where it makes sense to replace part of the URL string can be used to create a Quick Search.

Searching Google for "firefox tips":

One of my favorite uses is PHP documentation lookups:

