Override the default WordPress "shortlink" URL with one that has a custom text in it. You can also set a different base URL.
Generates pretty shorturls (without GET Params)
This is a plugin creating a shorter URL of post, page and media permalink.
A WordPress plugin that creates and adds support for shortened urls plus the shortlink auto-discovery tag
The ShortURL plugin provides short canonical permalinks to your posts and pages similarly to WordPress.com via its WP.me service.