Scroll your search engines

Once you have customized your search engines to your taste, adding, removing and sorting them with Firefox 2 new search engine manager, you can now quickly select a search engine by scrolling with the mouse wheel over the search engine bar, courtesy of Scroll Search Engines, developed by Einar Egilsson. Just install it, restart Firefox and scroll your search engines at will. 

Note that this extension seems to conflict with the Toolbar Drag and Drop extension as I couldn't them to work together.