There's a bunch of options available like tinyurl.com, bit.ly and many, many more. But, I decided to keep things in-house in order to maintain control. I created a quick, simple shortening service, http://xb2.us.
It's main purpose is to provide a way to automatically shorten the urls in Xbox America's twitter posts, but I decided to make an interface to allow other people to use it as well.
If any of you want to use it, feel free to: http://xb2.us