Rated 5 out of 5 stars
This extension does exactly what I was looking for in Firefox 4. It allows me to keep the menu bar, but remove the title bar. I always use Firefox in maximized mode, so title bar is just wasted space for me. However, I do use menu bar and I have some bookmarks sitting there, so I don't want to lose it. Once again, this add-on is great for this.
The only issue is that the minimize / restore / maximize buttons are pretty small. They could be larger.