There are users styles to expand the bookmarks toolbar into multi-rows. But I think a much better solution is to remove all icons from the toolbar and keep names short, just the toolbar not from within the folders on the toolbar.

Bookmarks Toolbar Fx4 Blue/Folders, Red/Bookmarks - Themes and Skins for Browser

http://userstyles.org/styles/46947

Multi Row BookmarksToolbar(Fx3.7a1pre Fx3.6a2pre) - Themes and Skins for Browser

http://userstyles.org/styles/20199

The "K" folder on my bookmarks toolbar contains mostly keyword shortcuts most of which are bookmarklets, along with references to support and mozillazine articles. So I don't really need many bookmarks showing on the toolbar.

Firefox Keyword Shortcuts

http://dmcritchie.mvps.org/firefox/kws.htm

How I work with the Bookmarks Toolbar has been explained in more detail in

https://support.mozilla.com/en-US/questions/847517

Additional questions: 1) So the only place one can put links/URLs is in the 'Bookmarks Toolbar items' folder? 2) And that one cannot have a second 'Bookmarks Toolbar items' folder (maybe named differently) on a different toolbar? 3) And the only way to sort-of do it anyway is to change a toolbar from single-row to multi-row?

I have--as test--just now managed to create a second 'Bookmarks Toolbar items' folder within the original one (via the Bookmarks menu), which results in a menu list when I click on it. For my purposes that will probably be good enough, since I don't really want all my favorite links continuously taking up screen space anyway. Grouping my links in (4) folders will work even better than multi-row. And this way I can get ALL my toolbars on a single row. So actually you have given me a VERY USEFUL solution, dmcritchie!

Thank you!

You can look at this extension:

• Multirow Bookmarks Toolbar Plus: https://addons.mozilla.org/firefox/addon/multirow-bookmarks-toolbarplus/

Yes, but....  :-)

Now with just a single bar across the top (the Menu bar), containing the standard menu items, 4 folders for my favorite links, navigation buttons, and the URL entry field, it looks so much cleaner! So please consider my original question as answered, even if the solution I chose was to REDUCE the number of rows instead of increasing them. Plz see my new question (Removing bookmark icons) for for more.

Thanks again!

There is one "Bookmarks Toolbar Items" container available for storing bookmarks, and that is where bookmarks are placed if you want them on a Toolbar. I have never seen an add-on that changes that by adding a 2nd "Bookmarks Toolbar Items" container.

I understand that you want to reduce the toolbar area at the top of the browser window, because I have been doing that for almost as long as I have been using Firefox (since 2002 when it was called Phoenix). The first thing I do is to get rid of or reduce the Menu Bar down to one button using one of the various Compact Menu extensions that have been available over the years. This is the one I currently use.
https://addons.mozilla.org/en-US/firefox/addon/compact-menu-2/
This extension hides the Menu Bar and places a button on the left side of the Navigation Bar upon installation. Click that blue globe button or hit the Alt key and the the Menubar Items appear in a drop-down menu. You can even drag that small button into the Customize Palette and use the Alt key to open the Menubar Items drop-down.
Hidden from view, but easily accessible when you need to use a Menubar Item.

OK! I can definitely live with a single "Bookmarks Toolbar Items" container, especially now after installing the "compact-menu-2/" add-on! And after seeing that the title bar changed, and that clicking on the now reddish-orange Firefox button in the title bar also accessed the most-used/useful items from the main toolbar's (sub)menus, even the blue globe isn't necessary! This is set by checking View --> Toolbars --> Show app button. But this also removes the text in the title bar, so I've UNchecked it; I like the text in the title bar.

Thank you the-edmeister!

Scott

• New Old Menu: https://addons.mozilla.org/firefox/addon/new-old-menu/

• Personal Menu (Personal Firefox Button): https://addons.mozilla.org/firefox/addon/personal-menu/