Have you been noticing those URL’s beginning with bit.ly? Bit.ly is a nice URL shortener making those “long and I don’t want to take the time to type” web addresses into something a bit easier. Fairly straight forward, you copy a long URL into the space provided at Bit.ly and you will get a shortened version. You can also create your own shortened URL’s if you create Bit.ly account.
How can you use them in a class? Used when asking anyone to go online to a specific webpage and you don't have an online link provided. Here is a URL searching Google news related to social networking: http://news.google.com/news/search?aq=f&pz=1&cf=all&ned=us&hl=en&q=social+networking and here is the corresponding Bit.ly URL: http://bit.ly/gK5Hvu