Try using the Add Bookmark Here ² extension:
https://addons.mozilla.org/en-US/firefox/addon/3880

I suggest you install the "Add Bookmark to Here2" extension, then you can expand the the list but you will not see the bookmark itself in the list if that is what you wanted. At the top you have three major folders you can select one of them and scroll up and down. Below that you have your most recently used folders and you can select one of them instead and scroll up and down. You can see the folder the bookmark is in -- they get added to the bottom

If you really want to see the bookmark within the folder the same extension allows you to bring the bookmark to the folder from say the bookmarks sidebar that is why it is named as such. I use it but mainly i use the dialog.

Please continue reading about bookmarks and some related extensions at

• http://kb.mozillazine.org/Sorting_and_rearranging_bookmarks_-_Firefox
• https://addons.mozilla.org/firefox/addon/add-bookmark-here-2/
• http://dmcritchie.mvps.org/firefox/firefox.htm#addbookmarkhere2
• http://dmcritchie.mvps.org/firefox/kws.htm

If you are not using tags at all, you can remove a whole lot of confusion by removing them from the dialog via the extension.

Well, I installed the recommended plug-in and restarted Firefox (did this twice in fact) - but it doesn't seem to create a change in the functionality of the bookmark dialogue box. I still can't grab the lower-left corner of the box and expand it - nor by doing anything else to the box (i.e. clicking on the big star, the folders with the small star, etc.) I'm not trying to see the individual bookmarks within the folders - just an expanded view of the bookmark tree when adding a new bookmark - much like what you can see when you go to the menu bar and click-on "Show All Bookmarks" - which brings up the bookmark tree structure, etc.

Did I do something wrong? Or is this plug-in not the appropriate one for this particular functionality?

Well, I installed the recommended plug-in and restarted Firefox (did this twice in fact) - but it doesn't seem to create a change in the functionality of the bookmark dialogue box. I still can't grab the lower-left corner of the box and expand it - nor by doing anything else to the box (i.e. clicking on the big star, the folders with the small star, etc.) I'm not trying to see the individual bookmarks within the folders - just an expanded view of the bookmark tree when adding a new bookmark - much like what you can see when you go to the menu bar and click-on "Show All Bookmarks" - which brings up the bookmark tree structure, etc.

Did I do something wrong? Or is this plug-in not the appropriate one for this particular functionality?

Strange the extension has a lot for me in it. You wanted bigger it is bigger, it doesn't fold up into a ball each time you bring it up -- stays expanded. It includes description and fills it in. It is further expandable by dragging bottom edge of folder display (strange but it works). I use keyword shortcuts so it is really important to me. I don't use tags and got rid of all of them and cleaned up the display by removing tag related items which confuse users. Did you read the author's home page, did you check out the additional context menu items, or my pages:

• Firefox Customizations (Notes)
  http://dmcritchie.mvps.org/firefox/firefox.htm#addbookmarkhere2
• http://dmcritchie.mvps.org/firefox/addbookmarkhere2.txt

Thanks for posting that image. That's not at all what the dialogue box looks like after I've installed the plug-in and restarted the browser - there seems to be no change whatsoever. I noticed that you are using the Windows OS - I use Mac OS, could this be a Mac vs. Windows issue? Maybe this plug-in meant only for Windows OS and I didn't see the fine print?

I can't re-size the window at all, can't move it, nothing. I've tried to get a screen shot of it - but my screen shot app won't grab it w/o me losing the window - anyway, no point in showing that image - it's simply the standard window you see prior to installing that plug-in.

To the right of of the drop-down is expand/contract same as on original. To expand the area inside drag the floor of the folders area and the floor of the description down from the inside to suit.. (picture has been modified)

Screen shots created and annotated using  PicPick  (free for personal use, Windows only)

FINALLY! SUCCESS!! Thank you SO MUCH! Yes, it's a little confusing and tedious - as you have to very delicately position the cursor in a very specific spot in order for it to change to the "line with downward facing arrow" cursor symbol - then it's possible to pull down the window to expand it - and it retains that size even if you close and then re-open it. GREAT! Thanks so much for everyone's help and timely input! I do appreciate it, and not I don't feel so claustrophobic when setting and organizing new bookmarks! ;D