Rated 5 out of 5 stars

Adds an IMHO essential function and works without any hassle. The only thing I would like to see added: support for URLs like "addons.mozilla.org"—it should be possible to go from there to "mozilla.org". (Admittedly, I have no idea how hard this would be to code; apparently it ain't trivial, otherwise the author would probably have taken care of it already.) Also, a SeaMonkey version would be nice to have; its lack is one of the things that keep me from using SeaMonkey more often.