If you are obsessed with microblogging services like Twitter and Identi.ca, you must be dealing with URL shortening services like TinyURL, Is.gd etc every now and then.
Though services like TinyURL help in reducing the mess and do a really good job in shrinking some really really long URLs, they also cloak the destination URLs which makes the user unaware of where he or she might be heading to.
LongURL Mobile Expander for Firefox simply does the opposite. Just like TinyURL takes a long URL and encodes it into a small one, LongURL for Firefox decodes the already encoded TinyURL and displays the actual destination as a tooltip.
This way users can preview the destination URLs without even clicking on them and decide whether they want to follow it or not. This not only helps them know the real location of the short URL but also saves them from shit load of Internet hoaxes, Rick Rolling videos, and who knows (even viruses and trojans?).
LongURL currently supports a number of URL shortening services e.g. TinyURL, Is.gd, Ping.fm etc.