This plugin will add new settings to your Settings -> Permalinks screen for you to
specify your blog’s shortlink structure. By default WordPress shortlinks look like
http://yrnxt.com/?p=153. Using this plugin you can specify every other structure
you like, e.g. http://yrnxt.com/~153.

Specifying new shortlink structures will never break WordPress’ default. Also when
changing the shortlink structure again afterwards old structures won’t break until you
explicitly remove them.

Take a look at the screenshots.