Although Short URL services are extremely handy when used in combination with a service like Twitter which has a 140 character limit, the scammers out there are making use of Short URLs as well to lure unsuspecting surfers onto phishing and malware sites; such an example can be seen here and is unfortunately all too commonplace.
Enter LongURL, which is a service that scans Short URLs before you visit the destination site.
As shown above, the Short URL is scanned and displayed in full.
The service supports the major shortening services like bit.ly and tinyurl, as well as a few hundred more of the obscure ones. It also has support for Firefox as an extension, or GreaseMonkey script. With this installed or bookmarked, its an extra layer of protection against finding yourself on a site you dont want to be on.
As the site itself points out: "So, then, I could send you this link http://is.gd/2kz and tell you to check out the photos from my recent trip, when in fact Im sending you to a video of Rick Astley singing "Never Gonna Give You Up". This is bad for users." Note: the link directs to a no longer available Rickroll!
So in short (hah!), dont get Rickrolled get LongURL.
Source: The Red Ferret