Ever wanted a customized folder on your Firefox Bookmarks bar that just shows whatever bookmarks that match your search terms?
Open up the bookmark organizer (Ctrl+Shift+B), do a search through your bookmarks, click Save, give it a name, and then drag the new search bar (at the bottom of the Bookmarks Menu) over to the Bookmarks bar (or wherever else you want it).
Want a better way to search for stuff on Craigslist? You might want to take a quick look through Craiglook, an alternate way to find what you’re looking for. They use the RSS feeds from Craigslist to let you search by distance through the classifieds.
If you want the Firefox Awesome Bar to give you search suggestions, act as a calculator, or add a spell-checker directly in the list without needing to waste time hitting the search results page, the CyberSearch extension is exactly what you need. Hit the download page for way more screenshots.