Rob (09.01.10, 12:09 AM): You can also track the links when you use those link shortening sites. Thats why I use custom naming of the links. This gives you a bit of SEO by allowing you to see how many people have clicked the link and where they clicked the link from.
Derrick (08.31.10, 9:10 PM): Thanks for the explanation! I have an account but don't tweet as I probably should but I do enjoy reading everyone's tweets. =)