There are a lot of URL shortening sites, but few that offer to expand the shortened URLs to their original state. Scammers, spammers, and hackers have taken advantage of shortened URLs to mislead and trick users into clicking them, only to have their information and accounts stolen or compromised.
However, LongURL is there to save the day. It does the opposite of what popular URL-shortening sites like TinyURL and bit.ly do, so you can see exactly where that shortened URL is leading you to and if you should avoid that link at all costs. LongURL supports a number of these URL-shortening websites, including the most-commonly used ones, so you might find it useful to bookmark the site for future reference.