I would have never added something like this except for the fact that it isn't available as an addon on the Firefox site.
The developer Tito stopped updating this one. The one I'm showing you was updated/modded to work with Firefox 3.0*
I just recently discovered it and thought I would share what I found.
-It counts links on a page
-Checks for error return codes in those links
-It will give you a list of all the links in a page in text or html form.
-You also have the options for all the links top open in new tabs or open each one individually.
I just thought it was pretty cool mostly for the fact that it will check links in a page and allow for a list of all the links.
Rather than me copying any information you can read more about it at the following site