perfect thing BUT Rated 4 out of 5 stars
missing custom makers of shortcuts, eg. goo.glThis review is for a previous version of the add-on (126.96.36.199-signed).
That's not true: You can specify your URL shortener by editing an about:config value: http://copy-shorturl.readthedocs.org/en/latest/serviceurl.html
Until very recently, Mozilla's add-ons SDK did not contain any way to make a preferences page for your add-on so that was an issue. I should be able to make editing the custom URL shorteners easier soon.