Steve

This plugin allows you to specify an alternative domain name to use with the built in URL shortening service.
For this to work it requires the chosen domain to be pointed / parked on the hosting account used for your blog.

Custom Shortlink Domain

Customise the domain name used to generate shortlink URLs.

karmacracy

With Karmacracy, you have fun while sharing links. Send cool links, while you improve yourself and get relevant: win awards, get domain clips, talk about revelant words as you get clicks sending good kcies, knowing new people and discovering new content. Check karmacracy and have fun!” />
This wordpress plugin will allow you to insert the widget from karmacracy in all your posts with just a button.

WP Karmacracy

Allows you to insert the Karmacracy Widget in your blog in an easy way.

Custom Shortlink Domain vs WP Karmacracy