This is again one of those little improvements that make LibreOffice much more usable, and that I so much love hacking on. I implemented a dropdown for the Open toolbar button that brings an easy access to the Recent Documents, and sent that the UX mailing list for feedback. I got some really useful hints. Even better - I gave Samuel code pointers to play with this a bit, and he came up with a beautiful patch that implements his ideas. And here is the result:
Samuel - thank you for this! :-) For anybody who would like to bring this functionality to the Start Center too (the screen you see when you start LibreOffice), here is an Easy Hack that will result in reusing the code for the Start Center too; and also will delete lots of duplicate code.