Advanced Bookmark Search
Allows you to search your bookmarks by name|description|url or ALL of them. It also helps to locate the complete path of a bookmark.
The manual of the extension (with some screenshots) can be located here: http://hlgeniusos.blogspot.com/
All the code is licensed under MPL GPL/LGPL so feel free to grab it and improve it :)
The extension is somewhat "inspired" by another one called Enhanced Bookmarks Search; they both share code originally developed by Netscape.
Please do not use this forum to request enhancements (I do not look at it periodically), send me an email instead.