To make a long story short: Shorl makes long URLs short.

What does do?

URLs tend to be long. Very long. In fact, they tend to be too long. If you've ever sent or received a long URL into an email message, you may have noticed that it wrapped into two lines or more. This often breaks common behavior, such as clickable links (only part of the URL becomes an 'active' link), and also makes it impossible to copy-and-paste the URL to a web browser in one move. makes URLs shorter, eliminating these problems.

What is this koremutake thing you're yapping about?

Have you not read the koremutake page? Then do.