Folder Bar in Nautilus

I just learned something today. If you go into Nautilus (the file browser for Ubuntu), you can see on the left there is a bar with your home folder, Desktop, Trash, etc. on it. Below that are a list of folders, probably Documents, Music, Ubuntu One (if you're running Karmic). You can drag and drop folders onto that list in order to access them quicker! The random little things you discover.