When I first saw, "tiny.url" cropping up all over the place I wondered thought, Wow, what a popular website. So many people are linking to it. That was several years ago and I had no idea that tinyurl (and snipurl and bit.ly, etc..) were "shortened" or "masked" urls. Shortened urls allow you to take create a new url from an unwieldy long "http:" address. This is particularly helpful for adding links to a TWITTER tweet which is limited to only 140 characters.
Like all good things, shortened urls began being used in not so good ways (to hide urls of questionable websites, for example). Because of this many school servers began blocking them. If you use Twitter as a form of professional development and shortened urls are blocked at your workplace, you will miss some potentially useful information.
HOW TO FIND THE REAL URL OF A SHORTENED ONE
The easiest way to get the real url of a shortened on is to go to this website:
Here you can copy and paste the short url into the form after which the correct url address is displayed. You can click it and be redirected to the site in a matter of seconds without it being blocked.
Just one more away to keep good information free and unrestricted.