If you aren't careful, bookmarking and searching can quickly get out of control on you. Here are 30+ tools to help you keep them under control in Firefox.
See also: 23 Best Social Networking Toolbars and Plugins for Firefox
Bookmarks
2 Pane Bookmark - Splits your bookmarks in to two panes, the top one showing the folders, the bottom one showing the folder's contents.
Annotea Ubimarks - Adds the Annotea social bookmarks and topics to your Firefox browser. Can update locally and then publish.
Bookmark Duplicate Detector - Detects duplicates in your bookmark as you add one, and can also search out existing duplicates and get rid of them.
Bookmark Sync and Sort - Lets you sync your bookmarks with an XML file to keep them backed up and download elsewhere.
Bookmark Tags - Store your bookmarks by tags instead of folders making it easier to find what you're looking for.
Boox - Gives you styled bookmarks, view live feeds as a web page, enhanced search and more.
del.icio.us Bookmarks - Integrates your del.icio.us bookmarks in to your browser giving you quick access to search them, organize, share them, and more.
Enhanced Bookmark Search - Not only gives you a more powerful search, but makes it easier to reach them by adding a toolbar button.
Firefox Google Bookmarks - Create a menu to access Google bookmarks, add your existing Firefox bookmarks to Google and more.
Flat Bookmark Editing - Allows you to edit bookmarks without going in to their properties.
Foxmarks Bookmark Synchronizer - Works in the background to backup your bookmarks, and if you use Firefox on multiple computers, to automatically sync their bookmarks.
gBrain - When activated, your browser history is saved to your Google Bookmarks so you can search it from any computer.
GMarks - Lets you migrate to-and-from Google Bookmarks, has filters, batch editing and more.
OnlineBookmarkManager Synchronizer - Syncs your bookmarks with the Online Bookmark Manager and let's you sync between multiple computers.
Smart Bookmarks Bar - Makes all your bookmarking links into icons until you hover your mouse over them, then they expand to include words.
Yoono - Not only suggests sites to you based on other users recommendations, but allows you to synchronize your bookmarks across multiple computers.
Searching
Add to Search Bar - Adds any website's search functionality to your built-in quick access search bar in Firefox.
BetterSearch - Adds thumbnails to your searches on Google, MSN Search, Yahoo Search, A9, Answers.com, AllTheWeb, Dogpile.com, del.icio.us and Simpy.com.
ConQuery - Makes the search bar work with the context menu for faster searches.
Context Search - Allows you to choose a specific search engine every time you use the "Search for" function.
Cooliris Previews - Lets you preview search results in Yahoo without clicking through. Also does automatic subsearches, send results with one click and more.
CustomizeGoogle - Customizes Google search pages with links to other search engines and removes ads.
Googlepedia - A tool for research making Google and Wikipedia work together; search in one affects the other.
GoogleHotKeys - Navigate Google search results just using hot key commands.
GooglePreview - Adds a thumbnail of the page in the results so you get a preview.
Organize Search Engines - Separate your growing list of installed search engines into folders and use separators.
Search Images on Google With a Single Click - Highlight a word, right click it for a pop-up menu, and you're searching Google Images for pictures of that word.
SearchLoad Options - Assists in managing the searchbar by clearing and resetting it at intervals you set.
searchOnTab - Lets you choose where the results of the search bar open.
SmartSearch - Highlight a word, right click and start searching with your bookmarked searches.
TrackMeNot - Helps conceal your true search history by submitting random queries to popular websites.