Rated 3 out of 5 stars
Expands only goo.gl shortened urls. Useless
In 2011 and Firefox 4, thousands of extensions but not ONE url expander, unshortener (whatever you name it), there were some for Firefox 3.x, none updated. This purpose seems essential, and scripts I've found here and there are mostly Tweeter restricted.
So, if you are skilled and are searching for a useful extension to code, go ahead, please !!