If you use Firefox or Iceweasel as I do, you may wonder about the "Desktop" and "Download" directories it creates every time you save anything to disk, even if you explicitly set ff to ask you where to save your stuff. This can be prevented by creating a ~/.config/user-dirs.dirs file, either with or without real content. This is according to http://www.kariliq.nl/misc/firefox-dirs.html and also this old arch forum post: https://bbs.archlinux.org/viewtopic.php?pid=997084#p997084