YOURLS will allow you to run your own URL shortening service (a la TinyURL). You can make it private or public, you can pick custom keyword URLs, it comes with its own API. You will love it.
Features:
- Private (your links only) or Public (everybody can create short links, fine for an intranet)
- Sequential or custom URL keyword
- Handy bookmarklets to easily shorten and share links
- Awesome stats: historical click reports, referrers tracking, visitors geo-location
- Neat Ajaxed interface
- Terrific Plugin architecture to easily implement new features
- Cool developer API
- Full jsonp support
- Friendly installer
- Sample files to create your own public interface and more