PLEASE update for FF 26+!
Not only does it show you whatever you want to know about your downloads' progress, but it does so in a small, unobtrusive manner that shows you your data without ever getting in the way!
Furthermore, I'm able to scan every file I download without having to manually call my virus scanner! Download Statusbar does it for me.
There is so much more to this little, out of the way extension that you'll find, like me, that you can't live without it!