Short (or tiny) URL's are great for sharing links on various social media services. Twitter's 140 character limit places a premium on bytes better used for words than URL's, e-mail clients get hinky with long URL's, and so on. It's possible to use services like tinyurl.com or bit.ly to create your short links, but as Drupal users we have a powerful platform at our fingertips. Maybe it can do the short URL natively or maybe it can be programmed to automatically retrieve short URL's from the existing services.