For those using social networks, especially twitter, URL shorteners have become a way of life and a staple of their tool set. They allow long URLs to be pasted into status and messages using a minimum of characters. While there are many services to choose from, there's inherit risks involved, so be careful what you click on. It is interesting that there is money to be made in this space, due to all the demand, and that's a bit more than some of the other services can say. Twitter has yet to make any real money, although they say they're working on it.
Meanwhile, who knew social networking had a dangerous side to it? Sure, there's always the risk that you'll say something that offends, or that the high schoolers out there will post - ahem - inappropriate photos, but that was largely the extent of it. However, consider the case of the head of MI6 (that's 007's boss for all your James Bond fans out there) who's wife ousted his identity on Facebook. Wow, all those spy movies were right; you really can't trust anyone!