Enough people loved Firefox's history and bookmark searching location bar that the name "AwesomeBar" caught on. While this tool is great for productivity, its omniscience is a serious privacy concern. Don't let your boss see that you've been looking for a new career on job search Web sites. You can clear your history, and completely exclude bookmarks from displaying in the bar, but why waste such a useful feature just to hide a few URLs? NotAwesome is a simple, free add-on that allows you to selectively hide bookmarks from the incriminating gaze of the AwesomeBar.
NotAwesome is simple to use. When adding a bookmark, just check the box labeled "Hide from AwesomeBar Searches." It's that easy for editing existing bookmarks too. NotAwesome is still in its early stages of development, so this is really all it does. However, new versions will likely include more customizability, such as a feature to allow mass bookmark hiding already mentioned by the developer. NotAwesome isn't a comprehensive privacy tool by any means, but it is a good solution if you're only worried about a few bookmarks.
Note: This is an experimental add-on for Firefox. To install it, you will have to check a box saying that you understand this.