I haven’t been back to the single-line command input on Firebug for a long time but over the weekend I noticed it had auto complete. Chrome has had this for a number of releases but I thought the way Firebug implemented it was very useful!
If you have other tabs open and don’t want to clear your authentication on other websites you can do the following in Firefox and Internet Explorer (IE):
Nice way to quickly change your authentication.
FYI – this does not work in Chrome.