Multi-row Bookmarks Toolbar

Mozilla Firefox users, who like to put many bookmarks in the Bookmarks Toolbar, sometimes get to the point where the number of bookmarks is too much to fit on the screen; so Firefox gives a drop-down menu at the end of the Bookmarks Toolbar, to access bookmarks not displayed on the toolbar.

Some users have used some simple methods of fitting more bookmarks on the Bookmarks Toolbar. These include renaming bookmarks [Right-click -> Properties], to give them shorter names. If a bookmark has its own unique favicon, removing the entire bookmark name will work.

I recently came across a neat little userChrome.css script that will cause the Bookmarks Toolbar to start another row, if the current one cannot fit all bookmarks.

Just add the following script to your userChrome.css file:
#bookmarks-ptf {display:block !important;}
#bookmarks-ptf toolbarseparator {display:inline !important;}