Easty to use Rated 4 out of 5 stars
Cool, but sometimes you can't add a url (the add button doesn't do anything) and you have no idea why. Sometimes I can close the tool window, open it again, re-enter the same url and it works.
Update: Filed a bug per the dev's request. Bumped to 4 stars since I am running a current Nightly build of Firefox.
As of version 2.0.0, the only "validation" on that box that triggers enable/disable of the Add button is that you have to have at least one character in there. If you are able to reproduce the behavior, let me know by filing an issue over at http://code.google.com/p/firefox-ntlmauth/issues/list - I'd love to fix it for you... I just can't see what you're seeing. :(